diff --git a/data/schemas/schemas_openxmlformats_org_presentationml_2006_main.json b/data/schemas/schemas_openxmlformats_org_presentationml_2006_main.json
index 21acb2e95..8dc29f0b7 100644
--- a/data/schemas/schemas_openxmlformats_org_presentationml_2006_main.json
+++ b/data/schemas/schemas_openxmlformats_org_presentationml_2006_main.json
@@ -6225,6 +6225,26 @@
             ]
           }
         ]
+      },
+      "ExtensionChildren": [
+
+        {
+          "Name": "p:CT_Picture/p:pic",
+          "PropertyName": "Picture"
+        }
+      ],
+      "ExtensionParticle": {
+        "Kind": "Sequence",
+        "Items": [
+          {
+            "Name": "p:CT_Picture/p:pic",
+            "Occurs": [
+              {
+                "Max": 1
+              }
+            ]
+          }
+        ]
       }
     },
     {
diff --git a/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/DataModelWriterExtensions.cs b/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/DataModelWriterExtensions.cs
index 64a214cc8..fdab99070 100644
--- a/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/DataModelWriterExtensions.cs
+++ b/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/DataModelWriterExtensions.cs
@@ -216,7 +216,15 @@ private static void WriteType(this IndentedTextWriter writer, OpenXmlGeneratorSe
         writer.Write("partial class ");
         writer.Write(className);
         writer.Write(" : ");
-        writer.WriteLine(GetBaseName(element));
+
+        if (element.KnownChildren is not null && element.KnownChildren.Any(c => c.QName.Name == "extLst") && element.ExtensionChildren is not null)
+        {
+            writer.WriteLine($"{GetBaseName(element)}, IExtensionChildrenParent<{className}>");
+        }
+        else
+        {
+            writer.WriteLine(GetBaseName(element));
+        }
 
         using (writer.AddBlock(new() { AddNewLineBeforeClosing = true, IncludeTrailingNewline = false }))
         {
@@ -320,6 +328,24 @@ static DocumentCommentOptions BuildTypeComments(OpenXmlGeneratorServices service
 
     private static void WriteMetadata(this IndentedTextWriter writer, OpenXmlGeneratorServices services, SchemaType containingType)
     {
+        if (containingType.KnownChildren is not null && containingType.KnownChildren.Any(c => c.QName.Name == "extLst") && containingType.ExtensionChildren is not null)
+        {
+            writer.WriteLine("public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {");
+
+            foreach (var child in containingType.ExtensionChildren)
+            {
+                writer.WriteLine($"    {services.FindClassName(child.Name)}.ElementType,");
+            }
+
+            writer.WriteLine("};");
+            writer.WriteLine();
+
+            //writer.WriteLine("public static IEnumerable<OpenXmlSchemaType> GetExtensionChildren<T>()");
+            //writer.WriteLine("    where T : IExtensionChildrenParent<T>");
+            //writer.WriteLine("    => T.ExtensionChildren;");
+            //writer.WriteLine();
+        }
+
         var attributes = containingType.Attributes;
 
         writer.WriteLine("internal override void ConfigureMetadata(ElementMetadata.Builder builder)");
@@ -356,16 +382,32 @@ private static void WriteMetadata(this IndentedTextWriter writer, OpenXmlGenerat
                 writer.WriteLine(";");
             }
 
-            if (!containingType.IsDerived)
+            if (!containingType.IsDerived && containingType.KnownChildren is not null)
             {
                 foreach (var child in containingType.KnownChildren)
                 {
                     var className = services.FindClassName(child);
 
                     writer.Write("builder.AddChild(");
-                    writer.Write(className);
+                    if (containingType.Name.QName.Name == "sldId" && containingType.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+                    {
+                        writer.Write($"{className}<DocumentFormat.OpenXml.Presentation.SlideId>");
+                    }
+                    else
+                    {
+                        writer.Write(className);
+                    }
+
                     writer.Write(".ElementType, static () => new ");
-                    writer.Write(className);
+                    if (containingType.Name.QName.Name == "sldId" && containingType.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+                    {
+                        writer.Write($"{className}<DocumentFormat.OpenXml.Presentation.SlideId>");
+                    }
+                    else
+                    {
+                        writer.Write(className);
+                    }
+
                     writer.WriteLine("());");
                 }
             }
@@ -490,20 +532,53 @@ private static void WriteElement(this IndentedTextWriter writer, OpenXmlGenerato
         }
 
         writer.Write("public ");
-        writer.Write(className);
+
+        if (parent.Name.QName.Name == "sldId" && parent.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+        {
+            writer.Write(string.Concat(className, "<DocumentFormat.OpenXml.Presentation.SlideId>"));
+        }
+        else
+        {
+            writer.Write(className);
+        }
+
         writer.Write("? ");
         writer.WriteLine(element.PropertyName);
 
         using (writer.AddBlock(new() { IncludeTrailingNewline = false }))
         {
             writer.Write("get => GetElement(");
-            writer.Write(className);
+            if (parent.Name.QName.Name == "sldId" && parent.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+            {
+                writer.Write("DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>");
+            }
+            else
+            {
+                writer.Write(className);
+            }
+
             writer.Write(".ElementType) as ");
-            writer.Write(className);
+            if (parent.Name.QName.Name == "sldId" && parent.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+            {
+                writer.Write("DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>");
+            }
+            else
+            {
+                writer.Write(className);
+            }
+
             writer.WriteLine(";");
 
             writer.Write("set => SetElement(value, ");
-            writer.Write(className);
+            if (parent.Name.QName.Name == "sldId" && parent.Name.QName.Prefix == "p" && className == "DocumentFormat.OpenXml.Presentation.ExtensionList")
+            {
+                writer.Write("DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>");
+            }
+            else
+            {
+                writer.Write(className);
+            }
+
             writer.WriteLine(".ElementType);");
         }
     }
diff --git a/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/ParticleWriterExtensions.cs b/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/ParticleWriterExtensions.cs
index b83d05197..c5ea453da 100644
--- a/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/ParticleWriterExtensions.cs
+++ b/gen/DocumentFormat.OpenXml.Generator.Models/Generators/Elements/ParticleWriterExtensions.cs
@@ -61,7 +61,15 @@ private static void WriteCompositeObject(this IndentedTextWriter writer, OpenXml
                 foreach (var item in p.Items)
                 {
                     list.AddDelimiter();
-                    writer.WriteItemNode(services, containingType, item);
+
+                    if (containingType.Name.QName.Name == "sldId" && containingType.Name.QName.Prefix == "p" && item.Name.QName.Name == "extLst" && item.Name.QName.Prefix == "p")
+                    {
+                        writer.Write("new ElementParticle(DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>.ElementType, 0, 1),");
+                    }
+                    else
+                    {
+                        writer.WriteItemNode(services, containingType, item);
+                    }
                 }
 
                 writer.WriteLine();
diff --git a/gen/DocumentFormat.OpenXml.Generator.Models/Models/SchemaType.cs b/gen/DocumentFormat.OpenXml.Generator.Models/Models/SchemaType.cs
index 4b705cfa1..da811a0f8 100644
--- a/gen/DocumentFormat.OpenXml.Generator.Models/Models/SchemaType.cs
+++ b/gen/DocumentFormat.OpenXml.Generator.Models/Models/SchemaType.cs
@@ -73,4 +73,8 @@ static void Fill(Particle? p, List<Particle> list)
     public IEnumerable<Validator> Validators { get; set; } = Enumerable.Empty<Validator>();
 
     public Particle? Particle { get; set; }
+
+    public IEnumerable<SchemaElement> ExtensionChildren { get; set; } = Enumerable.Empty<SchemaElement>();
+
+    public Particle? ExtensionParticle { get; set; }
 }
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_2020_mipLabelMetadata.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_2020_mipLabelMetadata.g.cs
index 2fb9b338d..fc470caf2 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_2020_mipLabelMetadata.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_2020_mipLabelMetadata.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2021.MipLabelMetaData
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.MipLabelMetaData.ClassificationLabel" /> <c>&lt;clbl:label></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ClassificationLabelList : OpenXmlPartRootElement
+    public partial class ClassificationLabelList : OpenXmlPartRootElement, IExtensionChildrenParent<ClassificationLabelList>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/2020/mipLabelMetadata", "labelList");
@@ -67,6 +67,9 @@ public ClassificationLabelList(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2007_8_2_chart.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2007_8_2_chart.g.cs
index 053da302f..eda2d9af0 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2007_8_2_chart.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2007_8_2_chart.g.cs
@@ -406,7 +406,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2007/8/2/chart", "spPr");
@@ -455,6 +455,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2008_diagram.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2008_diagram.g.cs
index 5b245aca2..e2ae840ff 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2008_diagram.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2008_diagram.g.cs
@@ -197,7 +197,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "cNvPr");
@@ -286,6 +286,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -369,7 +372,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingShapeProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "cNvSpPr");
@@ -418,6 +421,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -584,7 +590,7 @@ public DocumentFormat.OpenXml.Office.Drawing.NonVisualDrawingShapeProperties? No
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "spPr");
@@ -633,6 +639,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1151,7 +1160,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupDrawingShapeProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupDrawingShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupDrawingShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "cNvGrpSpPr");
@@ -1190,6 +1199,9 @@ public NonVisualGroupDrawingShapeProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1350,7 +1362,7 @@ public DocumentFormat.OpenXml.Office.Drawing.NonVisualGroupDrawingShapePropertie
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "grpSpPr");
@@ -1399,6 +1411,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1481,7 +1496,7 @@ public DocumentFormat.OpenXml.Drawing.TransformGroup? TransformGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.ShapeNonVisualProperties" /> <c>&lt;dsp:nvSpPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape : OpenXmlCompositeElement
+    public partial class Shape : OpenXmlCompositeElement, IExtensionChildrenParent<Shape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "sp");
@@ -1530,6 +1545,9 @@ public StringValue? ModelId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1659,7 +1677,7 @@ public DocumentFormat.OpenXml.Office.Drawing.OfficeArtExtensionList? OfficeArtEx
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.Shape" /> <c>&lt;dsp:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShape : GroupShapeType
+    public partial class GroupShape : GroupShapeType, IExtensionChildrenParent<GroupShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "grpSp");
@@ -1698,6 +1716,9 @@ public GroupShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1735,7 +1756,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.Shape" /> <c>&lt;dsp:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeTree : GroupShapeType
+    public partial class ShapeTree : GroupShapeType, IExtensionChildrenParent<ShapeTree>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2008/diagram", "spTree");
@@ -1774,6 +1795,9 @@ public ShapeTree(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1811,7 +1835,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.Shape" /> <c>&lt;dsp:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class GroupShapeType : OpenXmlCompositeElement
+    public abstract partial class GroupShapeType : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -1850,6 +1874,9 @@ protected GroupShapeType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_chartDrawing.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_chartDrawing.g.cs
index e56e5379a..e4b518d72 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_chartDrawing.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_chartDrawing.g.cs
@@ -32,7 +32,7 @@ namespace DocumentFormat.OpenXml.Office2010.Drawing.ChartDrawing
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ChartDrawing.NonVisualContentPartProperties" /> <c>&lt;cdr14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPart : OpenXmlCompositeElement
+    public partial class ContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/chartDrawing", "contentPart");
@@ -94,6 +94,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -190,7 +193,7 @@ public DocumentFormat.OpenXml.Office2010.Drawing.ChartDrawing.OfficeArtExtension
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/chartDrawing", "cNvPr");
@@ -279,6 +282,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -362,7 +368,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ContentPartLocks" /> <c>&lt;a14:cpLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement
+    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualInkContentPartProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/chartDrawing", "cNvContentPartPr");
@@ -411,6 +417,9 @@ public BooleanValue? IsComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_diagram.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_diagram.g.cs
index 9b2f0b0df..741cc8530 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_diagram.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_diagram.g.cs
@@ -30,7 +30,7 @@ namespace DocumentFormat.OpenXml.Office2010.Drawing.Diagram
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/diagram", "cNvPr");
@@ -119,6 +119,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_main.g.cs
index 0a7040cb1..1846ad6ce 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_main.g.cs
@@ -176,7 +176,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.NonVisualContentPartProperties" /> <c>&lt;a14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GvmlContentPart : OpenXmlCompositeElement
+    public partial class GvmlContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<GvmlContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "contentPart");
@@ -238,6 +238,9 @@ public StringValue? RelationshipId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -536,7 +539,7 @@ public DocumentFormat.OpenXml.Drawing.GroupFill? GroupFill
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HiddenLineProperties : OpenXmlCompositeElement
+    public partial class HiddenLineProperties : OpenXmlCompositeElement, IExtensionChildrenParent<HiddenLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "hiddenLine");
@@ -615,6 +618,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PenAlignmentValues>? Alignment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -803,7 +809,7 @@ public DocumentFormat.OpenXml.Drawing.EffectDag? EffectDag
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HiddenScene3D : OpenXmlCompositeElement
+    public partial class HiddenScene3D : OpenXmlCompositeElement, IExtensionChildrenParent<HiddenScene3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "hiddenScene3d");
@@ -842,6 +848,9 @@ public HiddenScene3D(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -931,7 +940,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HiddenShape3D : OpenXmlCompositeElement
+    public partial class HiddenShape3D : OpenXmlCompositeElement, IExtensionChildrenParent<HiddenShape3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "hiddenSp3d");
@@ -1010,6 +1019,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PresetMaterialTypeValues>? Prese
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1352,7 +1364,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.OfficeArtExtensionList" /> <c>&lt;a14:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPartLocks : OpenXmlCompositeElement
+    public partial class ContentPartLocks : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPartLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "cpLocks");
@@ -1491,6 +1503,9 @@ public BooleanValue? NoChangeShapeType
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3950,7 +3965,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "cNvPr");
@@ -4039,6 +4054,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4122,7 +4140,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ContentPartLocks" /> <c>&lt;a14:cpLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement
+    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualInkContentPartProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/main", "cNvContentPartPr");
@@ -4171,6 +4189,9 @@ public BooleanValue? IsComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_slicer.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_slicer.g.cs
index ee0488213..57e10bcb6 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_slicer.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2010_slicer.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2010.Drawing.Slicer
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.Slicer.OfficeArtExtensionList" /> <c>&lt;sle:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Slicer : OpenXmlCompositeElement
+    public partial class Slicer : OpenXmlCompositeElement, IExtensionChildrenParent<Slicer>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2010/slicer", "slicer");
@@ -77,6 +77,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chart.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chart.g.cs
index 1930955f7..ea7c6e64b 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chart.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chart.g.cs
@@ -31,7 +31,7 @@ namespace DocumentFormat.OpenXml.Office2013.Drawing.Chart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PivotTableName" /> <c>&lt;c:name></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotSource : OpenXmlCompositeElement
+    public partial class PivotSource : OpenXmlCompositeElement, IExtensionChildrenParent<PivotSource>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "pivotSource");
@@ -70,6 +70,9 @@ public PivotSource(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -211,7 +214,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "spPr");
@@ -260,6 +263,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -352,7 +358,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ManualLayout" /> <c>&lt;c:manualLayout></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Layout : OpenXmlCompositeElement
+    public partial class Layout : OpenXmlCompositeElement, IExtensionChildrenParent<Layout>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "layout");
@@ -391,6 +397,9 @@ public Layout(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2408,7 +2417,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.StringLiteral? StringLiteral
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BarChartSeries : OpenXmlCompositeElement
+    public partial class BarChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<BarChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -2447,6 +2456,9 @@ public BarChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2597,7 +2609,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LineChartSeries : OpenXmlCompositeElement
+    public partial class LineChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<LineChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -2636,6 +2648,9 @@ public LineChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2787,7 +2802,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ScatterChartSeries : OpenXmlCompositeElement
+    public partial class ScatterChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<ScatterChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -2826,6 +2841,9 @@ public ScatterChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2959,7 +2977,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Marker? Marker
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AreaChartSeries : OpenXmlCompositeElement
+    public partial class AreaChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<AreaChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -2998,6 +3016,9 @@ public AreaChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3128,7 +3149,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Explosion" /> <c>&lt;c:explosion></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PieChartSeries : OpenXmlCompositeElement
+    public partial class PieChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<PieChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -3167,6 +3188,9 @@ public PieChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3314,7 +3338,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Explosion? Explosion
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BubbleChartSeries : OpenXmlCompositeElement
+    public partial class BubbleChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<BubbleChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -3353,6 +3377,9 @@ public BubbleChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3504,7 +3531,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.InvertIfNegative? InvertIfNegative
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RadarChartSeries : OpenXmlCompositeElement
+    public partial class RadarChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<RadarChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -3543,6 +3570,9 @@ public RadarChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3684,7 +3714,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Marker? Marker
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SurfaceChartSeries : OpenXmlCompositeElement
+    public partial class SurfaceChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<SurfaceChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "ser");
@@ -3723,6 +3753,9 @@ public SurfaceChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3895,7 +3928,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.SurfaceSerExtensionList? SurfaceSer
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabelsRangeChache : StringDataType
+    public partial class DataLabelsRangeChache : StringDataType, IExtensionChildrenParent<DataLabelsRangeChache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "dlblRangeCache");
@@ -3934,6 +3967,9 @@ public DataLabelsRangeChache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3964,7 +4000,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabelFieldTableCache : StringDataType
+    public partial class DataLabelFieldTableCache : StringDataType, IExtensionChildrenParent<DataLabelFieldTableCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "dlblFieldTableCache");
@@ -4003,6 +4039,9 @@ public DataLabelFieldTableCache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4033,7 +4072,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class StringDataType : OpenXmlCompositeElement
+    public abstract partial class StringDataType : OpenXmlCompositeElement, IExtensionChildrenParent<StringDataType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -4072,6 +4111,9 @@ protected StringDataType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4154,7 +4196,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Symbol" /> <c>&lt;c:symbol></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Marker : OpenXmlCompositeElement
+    public partial class Marker : OpenXmlCompositeElement, IExtensionChildrenParent<Marker>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "marker");
@@ -4193,6 +4235,9 @@ public Marker(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4293,7 +4338,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Separator" /> <c>&lt;c:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabel : OpenXmlCompositeElement
+    public partial class DataLabel : OpenXmlCompositeElement, IExtensionChildrenParent<DataLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chart", "dLbl");
@@ -4332,6 +4377,9 @@ public DataLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chartStyle.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chartStyle.g.cs
index 40240c7b8..f8ce74702 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chartStyle.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_chartStyle.g.cs
@@ -35,7 +35,7 @@ namespace DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.ColorStyleVariation" /> <c>&lt;cs:variation></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorStyle : OpenXmlPartRootElement
+    public partial class ColorStyle : OpenXmlPartRootElement, IExtensionChildrenParent<ColorStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "colorStyle");
@@ -94,6 +94,9 @@ public UInt32Value? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -214,7 +217,7 @@ public ChartColorStylePart? ChartColorStylePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.Wall" /> <c>&lt;cs:wall></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartStyle : OpenXmlPartRootElement
+    public partial class ChartStyle : OpenXmlPartRootElement, IExtensionChildrenParent<ChartStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "chartStyle");
@@ -263,6 +266,9 @@ public UInt32Value? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1719,7 +1725,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "spPr");
@@ -1768,6 +1774,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1880,7 +1889,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UnderlineFollowsText" /> <c>&lt;a:uLnTx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextCharacterPropertiesType : OpenXmlCompositeElement
+    public partial class TextCharacterPropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<TextCharacterPropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "defRPr");
@@ -2109,6 +2118,9 @@ public StringValue? Bookmark
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2260,7 +2272,7 @@ public DocumentFormat.OpenXml.Drawing.Outline? Outline
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeAutoFit" /> <c>&lt;a:spAutoFit></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextBodyProperties : OpenXmlCompositeElement
+    public partial class TextBodyProperties : OpenXmlCompositeElement, IExtensionChildrenParent<TextBodyProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "bodyPr");
@@ -2489,6 +2501,9 @@ public BooleanValue? CompatibleLineSpacing
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3480,7 +3495,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AxisTitle : StyleEntry
+    public partial class AxisTitle : StyleEntry, IExtensionChildrenParent<AxisTitle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "axisTitle");
@@ -3519,6 +3534,9 @@ public AxisTitle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3561,7 +3579,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CategoryAxis : StyleEntry
+    public partial class CategoryAxis : StyleEntry, IExtensionChildrenParent<CategoryAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "categoryAxis");
@@ -3600,6 +3618,9 @@ public CategoryAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3642,7 +3663,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartArea : StyleEntry
+    public partial class ChartArea : StyleEntry, IExtensionChildrenParent<ChartArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "chartArea");
@@ -3681,6 +3702,9 @@ public ChartArea(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3723,7 +3747,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabel : StyleEntry
+    public partial class DataLabel : StyleEntry, IExtensionChildrenParent<DataLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataLabel");
@@ -3762,6 +3786,9 @@ public DataLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3804,7 +3831,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabelCallout : StyleEntry
+    public partial class DataLabelCallout : StyleEntry, IExtensionChildrenParent<DataLabelCallout>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataLabelCallout");
@@ -3843,6 +3870,9 @@ public DataLabelCallout(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3885,7 +3915,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPoint : StyleEntry
+    public partial class DataPoint : StyleEntry, IExtensionChildrenParent<DataPoint>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataPoint");
@@ -3924,6 +3954,9 @@ public DataPoint(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3966,7 +3999,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPoint3D : StyleEntry
+    public partial class DataPoint3D : StyleEntry, IExtensionChildrenParent<DataPoint3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataPoint3D");
@@ -4005,6 +4038,9 @@ public DataPoint3D(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4047,7 +4083,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPointLine : StyleEntry
+    public partial class DataPointLine : StyleEntry, IExtensionChildrenParent<DataPointLine>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataPointLine");
@@ -4086,6 +4122,9 @@ public DataPointLine(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4128,7 +4167,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPointMarker : StyleEntry
+    public partial class DataPointMarker : StyleEntry, IExtensionChildrenParent<DataPointMarker>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataPointMarker");
@@ -4167,6 +4206,9 @@ public DataPointMarker(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4209,7 +4251,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPointWireframe : StyleEntry
+    public partial class DataPointWireframe : StyleEntry, IExtensionChildrenParent<DataPointWireframe>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataPointWireframe");
@@ -4248,6 +4290,9 @@ public DataPointWireframe(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4290,7 +4335,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataTableStyle : StyleEntry
+    public partial class DataTableStyle : StyleEntry, IExtensionChildrenParent<DataTableStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dataTable");
@@ -4329,6 +4374,9 @@ public DataTableStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4371,7 +4419,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DownBar : StyleEntry
+    public partial class DownBar : StyleEntry, IExtensionChildrenParent<DownBar>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "downBar");
@@ -4410,6 +4458,9 @@ public DownBar(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4452,7 +4503,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DropLine : StyleEntry
+    public partial class DropLine : StyleEntry, IExtensionChildrenParent<DropLine>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "dropLine");
@@ -4491,6 +4542,9 @@ public DropLine(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4533,7 +4587,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ErrorBar : StyleEntry
+    public partial class ErrorBar : StyleEntry, IExtensionChildrenParent<ErrorBar>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "errorBar");
@@ -4572,6 +4626,9 @@ public ErrorBar(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4614,7 +4671,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Floor : StyleEntry
+    public partial class Floor : StyleEntry, IExtensionChildrenParent<Floor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "floor");
@@ -4653,6 +4710,9 @@ public Floor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4695,7 +4755,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GridlineMajor : StyleEntry
+    public partial class GridlineMajor : StyleEntry, IExtensionChildrenParent<GridlineMajor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "gridlineMajor");
@@ -4734,6 +4794,9 @@ public GridlineMajor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4776,7 +4839,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GridlineMinor : StyleEntry
+    public partial class GridlineMinor : StyleEntry, IExtensionChildrenParent<GridlineMinor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "gridlineMinor");
@@ -4815,6 +4878,9 @@ public GridlineMinor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4857,7 +4923,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HiLoLine : StyleEntry
+    public partial class HiLoLine : StyleEntry, IExtensionChildrenParent<HiLoLine>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "hiLoLine");
@@ -4896,6 +4962,9 @@ public HiLoLine(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4938,7 +5007,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LeaderLine : StyleEntry
+    public partial class LeaderLine : StyleEntry, IExtensionChildrenParent<LeaderLine>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "leaderLine");
@@ -4977,6 +5046,9 @@ public LeaderLine(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5019,7 +5091,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LegendStyle : StyleEntry
+    public partial class LegendStyle : StyleEntry, IExtensionChildrenParent<LegendStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "legend");
@@ -5058,6 +5130,9 @@ public LegendStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5100,7 +5175,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotArea : StyleEntry
+    public partial class PlotArea : StyleEntry, IExtensionChildrenParent<PlotArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "plotArea");
@@ -5139,6 +5214,9 @@ public PlotArea(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5181,7 +5259,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotArea3D : StyleEntry
+    public partial class PlotArea3D : StyleEntry, IExtensionChildrenParent<PlotArea3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "plotArea3D");
@@ -5220,6 +5298,9 @@ public PlotArea3D(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5262,7 +5343,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SeriesAxis : StyleEntry
+    public partial class SeriesAxis : StyleEntry, IExtensionChildrenParent<SeriesAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "seriesAxis");
@@ -5301,6 +5382,9 @@ public SeriesAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5343,7 +5427,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SeriesLine : StyleEntry
+    public partial class SeriesLine : StyleEntry, IExtensionChildrenParent<SeriesLine>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "seriesLine");
@@ -5382,6 +5466,9 @@ public SeriesLine(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5424,7 +5511,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TitleStyle : StyleEntry
+    public partial class TitleStyle : StyleEntry, IExtensionChildrenParent<TitleStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "title");
@@ -5463,6 +5550,9 @@ public TitleStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5505,7 +5595,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TrendlineStyle : StyleEntry
+    public partial class TrendlineStyle : StyleEntry, IExtensionChildrenParent<TrendlineStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "trendline");
@@ -5544,6 +5634,9 @@ public TrendlineStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5586,7 +5679,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TrendlineLabel : StyleEntry
+    public partial class TrendlineLabel : StyleEntry, IExtensionChildrenParent<TrendlineLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "trendlineLabel");
@@ -5625,6 +5718,9 @@ public TrendlineLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5667,7 +5763,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class UpBar : StyleEntry
+    public partial class UpBar : StyleEntry, IExtensionChildrenParent<UpBar>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "upBar");
@@ -5706,6 +5802,9 @@ public UpBar(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5748,7 +5847,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ValueAxis : StyleEntry
+    public partial class ValueAxis : StyleEntry, IExtensionChildrenParent<ValueAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "valueAxis");
@@ -5787,6 +5886,9 @@ public ValueAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5829,7 +5931,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Wall : StyleEntry
+    public partial class Wall : StyleEntry, IExtensionChildrenParent<Wall>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/chartStyle", "wall");
@@ -5868,6 +5970,9 @@ public Wall(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5910,7 +6015,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.ChartStyle.LineWidthScale" /> <c>&lt;cs:lineWidthScale></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class StyleEntry : OpenXmlCompositeElement
+    public abstract partial class StyleEntry : OpenXmlCompositeElement, IExtensionChildrenParent<StyleEntry>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -5959,6 +6064,9 @@ public ListValue<StringValue>? Modifiers
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_timeslicer.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_timeslicer.g.cs
index 372ba9f6d..fdf6b7786 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_timeslicer.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2012_timeslicer.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2013.Drawing.TimeSlicer
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Drawing.TimeSlicer.OfficeArtExtensionList" /> <c>&lt;tsle:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TimeSlicer : OpenXmlCompositeElement
+    public partial class TimeSlicer : OpenXmlCompositeElement, IExtensionChildrenParent<TimeSlicer>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2012/timeslicer", "timeslicer");
@@ -77,6 +77,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2013_main_command.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2013_main_command.g.cs
index 9c9e01855..8e6e916e3 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2013_main_command.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2013_main_command.g.cs
@@ -2766,7 +2766,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextParagraphPropertiesType : OpenXmlCompositeElement
+    public partial class TextParagraphPropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<TextParagraphPropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "pPr");
@@ -2915,6 +2915,9 @@ public BooleanValue? Height
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3074,7 +3077,7 @@ public DocumentFormat.OpenXml.Drawing.SpaceAfter? SpaceAfter
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeAutoFit" /> <c>&lt;a:spAutoFit></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextBodyProperties : OpenXmlCompositeElement
+    public partial class TextBodyProperties : OpenXmlCompositeElement, IExtensionChildrenParent<TextBodyProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "bodyPr");
@@ -3303,6 +3306,9 @@ public BooleanValue? CompatibleLineSpacing
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3647,7 +3653,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "spPr");
@@ -3696,6 +3702,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4689,7 +4698,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.Command.BwModeEmpty" /> <c>&lt;oac:bwMode></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ResetShapeProperties : OpenXmlCompositeElement
+    public partial class ResetShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ResetShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "spPr");
@@ -4728,6 +4737,9 @@ public ResetShapeProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6198,7 +6210,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "grpSpPr");
@@ -6247,6 +6259,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6329,7 +6344,7 @@ public DocumentFormat.OpenXml.Drawing.TransformGroup? TransformGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.Command.BwModeEmpty" /> <c>&lt;oac:bwMode></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ResetGroupShapeProperties : OpenXmlCompositeElement
+    public partial class ResetGroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ResetGroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "grpSpPr");
@@ -6368,6 +6383,9 @@ public ResetGroupShapeProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6485,7 +6503,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.Command.BwModeEmpty? BwModeEmpt
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProps : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProps : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProps>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "cNvPr");
@@ -6574,6 +6592,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6657,7 +6678,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupDrawingShapeProps : OpenXmlCompositeElement
+    public partial class NonVisualGroupDrawingShapeProps : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupDrawingShapeProps>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "cNvGrpSpPr");
@@ -6696,6 +6717,9 @@ public NonVisualGroupDrawingShapeProps(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7900,7 +7924,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LinePropertiesType : OpenXmlCompositeElement
+    public partial class LinePropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<LinePropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2013/main/command", "lineProps");
@@ -7979,6 +8003,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PenAlignmentValues>? Alignment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart.g.cs
index 9d59219b2..ac485a1ff 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart.g.cs
@@ -43,7 +43,7 @@ namespace DocumentFormat.OpenXml.Office2016.Drawing.Charts
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "spPr");
@@ -92,6 +92,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -332,7 +335,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Symbol" /> <c>&lt;c:symbol></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Marker : OpenXmlCompositeElement
+    public partial class Marker : OpenXmlCompositeElement, IExtensionChildrenParent<Marker>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "marker");
@@ -371,6 +374,9 @@ public Marker(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -471,7 +477,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Separator" /> <c>&lt;c:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DLbl : OpenXmlCompositeElement
+    public partial class DLbl : OpenXmlCompositeElement, IExtensionChildrenParent<DLbl>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "dLbl");
@@ -510,6 +516,9 @@ public DLbl(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1087,7 +1096,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.Charts.DLbl? DLbl
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.FormatCode" /> <c>&lt;c:formatCode></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NumberDataType : OpenXmlCompositeElement
+    public partial class NumberDataType : OpenXmlCompositeElement, IExtensionChildrenParent<NumberDataType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "numCache");
@@ -1126,6 +1135,9 @@ public NumberDataType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1266,7 +1278,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.Charts.NumberDataType? NumberDa
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StringDataType : OpenXmlCompositeElement
+    public partial class StringDataType : OpenXmlCompositeElement, IExtensionChildrenParent<StringDataType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "strCache");
@@ -1305,6 +1317,9 @@ public StringDataType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1430,7 +1445,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.Charts.StringDataType? StringDa
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MultiLvlStrData : OpenXmlCompositeElement
+    public partial class MultiLvlStrData : OpenXmlCompositeElement, IExtensionChildrenParent<MultiLvlStrData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart", "multiLvlStrCache");
@@ -1469,6 +1484,9 @@ public MultiLvlStrData(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart_ac.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart_ac.g.cs
index c81c71e4e..e404c524e 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart_ac.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chart_ac.g.cs
@@ -30,7 +30,7 @@ namespace DocumentFormat.OpenXml.Office2016.Drawing.ChartsAc
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MultiLvlStrData : OpenXmlCompositeElement
+    public partial class MultiLvlStrData : OpenXmlCompositeElement, IExtensionChildrenParent<MultiLvlStrData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chart/ac", "multiLvlStrLit");
@@ -69,6 +69,9 @@ public MultiLvlStrData(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chartex.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chartex.g.cs
index 6c9999dd6..e56925374 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chartex.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2014_chartex.g.cs
@@ -36,7 +36,7 @@ namespace DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.PrintSettings" /> <c>&lt;cx:printSettings></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartSpace : OpenXmlPartRootElement
+    public partial class ChartSpace : OpenXmlPartRootElement, IExtensionChildrenParent<ChartSpace>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "chartSpace");
@@ -75,6 +75,9 @@ public ChartSpace(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1575,7 +1578,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.StringDimension" /> <c>&lt;cx:strDim></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Data : OpenXmlCompositeElement
+    public partial class Data : OpenXmlCompositeElement, IExtensionChildrenParent<Data>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "data");
@@ -1624,6 +1627,9 @@ public UInt32Value? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2469,7 +2475,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.RichTextBody? Rich
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "spPr");
@@ -2518,6 +2524,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2612,7 +2621,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.Text" /> <c>&lt;cx:tx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AxisUnitsLabel : OpenXmlCompositeElement
+    public partial class AxisUnitsLabel : OpenXmlCompositeElement, IExtensionChildrenParent<AxisUnitsLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "unitsLabel");
@@ -2651,6 +2660,9 @@ public AxisUnitsLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2893,7 +2905,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.Text" /> <c>&lt;cx:tx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AxisTitle : OpenXmlCompositeElement
+    public partial class AxisTitle : OpenXmlCompositeElement, IExtensionChildrenParent<AxisTitle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "title");
@@ -2932,6 +2944,9 @@ public AxisTitle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3018,7 +3033,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AxisUnits : OpenXmlCompositeElement
+    public partial class AxisUnits : OpenXmlCompositeElement, IExtensionChildrenParent<AxisUnits>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "units");
@@ -3067,6 +3082,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.AxisUnit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3125,7 +3143,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MajorGridlinesGridlines : OpenXmlGridlinesElement
+    public partial class MajorGridlinesGridlines : OpenXmlGridlinesElement, IExtensionChildrenParent<MajorGridlinesGridlines>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "majorGridlines");
@@ -3164,6 +3182,9 @@ public MajorGridlinesGridlines(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3192,7 +3213,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MinorGridlinesGridlines : OpenXmlGridlinesElement
+    public partial class MinorGridlinesGridlines : OpenXmlGridlinesElement, IExtensionChildrenParent<MinorGridlinesGridlines>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "minorGridlines");
@@ -3231,6 +3252,9 @@ public MinorGridlinesGridlines(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3259,7 +3283,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class OpenXmlGridlinesElement : OpenXmlCompositeElement
+    public abstract partial class OpenXmlGridlinesElement : OpenXmlCompositeElement, IExtensionChildrenParent<OpenXmlGridlinesElement>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -3298,6 +3322,9 @@ protected OpenXmlGridlinesElement(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3343,7 +3370,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MajorTickMarksTickMarks : OpenXmlTickMarksElement
+    public partial class MajorTickMarksTickMarks : OpenXmlTickMarksElement, IExtensionChildrenParent<MajorTickMarksTickMarks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "majorTickMarks");
@@ -3382,6 +3409,9 @@ public MajorTickMarksTickMarks(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3408,7 +3438,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MinorTickMarksTickMarks : OpenXmlTickMarksElement
+    public partial class MinorTickMarksTickMarks : OpenXmlTickMarksElement, IExtensionChildrenParent<MinorTickMarksTickMarks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "minorTickMarks");
@@ -3447,6 +3477,9 @@ public MinorTickMarksTickMarks(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3473,7 +3506,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class OpenXmlTickMarksElement : OpenXmlCompositeElement
+    public abstract partial class OpenXmlTickMarksElement : OpenXmlCompositeElement, IExtensionChildrenParent<OpenXmlTickMarksElement>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -3522,6 +3555,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.TickMark
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3555,7 +3591,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TickLabels : OpenXmlCompositeElement
+    public partial class TickLabels : OpenXmlCompositeElement, IExtensionChildrenParent<TickLabels>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "tickLabels");
@@ -3594,6 +3630,9 @@ public TickLabels(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7447,7 +7486,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.SeparatorXsdstring" /> <c>&lt;cx:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabel : OpenXmlCompositeElement
+    public partial class DataLabel : OpenXmlCompositeElement, IExtensionChildrenParent<DataLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "dataLabel");
@@ -7506,6 +7545,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.DataLabe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7911,7 +7953,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.MaxValueColorEndPo
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPoint : OpenXmlCompositeElement
+    public partial class DataPoint : OpenXmlCompositeElement, IExtensionChildrenParent<DataPoint>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "dataPt");
@@ -7960,6 +8002,9 @@ public UInt32Value? Idx
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8027,7 +8072,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.SeparatorXsdstring" /> <c>&lt;cx:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabels : OpenXmlCompositeElement
+    public partial class DataLabels : OpenXmlCompositeElement, IExtensionChildrenParent<DataLabels>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "dataLabels");
@@ -8076,6 +8121,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.DataLabe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8238,7 +8286,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.Subtotals" /> <c>&lt;cx:subtotals></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SeriesLayoutProperties : OpenXmlCompositeElement
+    public partial class SeriesLayoutProperties : OpenXmlCompositeElement, IExtensionChildrenParent<SeriesLayoutProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "layoutPr");
@@ -8277,6 +8325,9 @@ public SeriesLayoutProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8408,7 +8459,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotSurface : OpenXmlCompositeElement
+    public partial class PlotSurface : OpenXmlCompositeElement, IExtensionChildrenParent<PlotSurface>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "plotSurface");
@@ -8447,6 +8498,9 @@ public PlotSurface(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8511,7 +8565,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.AxisId" /> <c>&lt;cx:axisId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Series : OpenXmlCompositeElement
+    public partial class Series : OpenXmlCompositeElement, IExtensionChildrenParent<Series>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "series");
@@ -8600,6 +8654,9 @@ public UInt32Value? FormatIdx
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8708,7 +8765,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ValueColorPosition
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.Series" /> <c>&lt;cx:series></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotAreaRegion : OpenXmlCompositeElement
+    public partial class PlotAreaRegion : OpenXmlCompositeElement, IExtensionChildrenParent<PlotAreaRegion>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "plotAreaRegion");
@@ -8747,6 +8804,9 @@ public PlotAreaRegion(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8803,7 +8863,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.PlotSurface? PlotS
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ValueAxisScaling" /> <c>&lt;cx:valScaling></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Axis : OpenXmlCompositeElement
+    public partial class Axis : OpenXmlCompositeElement, IExtensionChildrenParent<Axis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "axis");
@@ -8862,6 +8922,9 @@ public BooleanValue? Hidden
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8925,7 +8988,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.Text" /> <c>&lt;cx:tx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartTitle : OpenXmlCompositeElement
+    public partial class ChartTitle : OpenXmlCompositeElement, IExtensionChildrenParent<ChartTitle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "title");
@@ -8994,6 +9057,9 @@ public BooleanValue? Overlay
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9086,7 +9152,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.PlotAreaRegion" /> <c>&lt;cx:plotAreaRegion></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotArea : OpenXmlCompositeElement
+    public partial class PlotArea : OpenXmlCompositeElement, IExtensionChildrenParent<PlotArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "plotArea");
@@ -9125,6 +9191,9 @@ public PlotArea(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9173,7 +9242,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.PlotAreaRegion? Pl
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Legend : OpenXmlCompositeElement
+    public partial class Legend : OpenXmlCompositeElement, IExtensionChildrenParent<Legend>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "legend");
@@ -9242,6 +9311,9 @@ public BooleanValue? Overlay
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9317,7 +9389,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList" /> <c>&lt;cx:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FormatOverride : OpenXmlCompositeElement
+    public partial class FormatOverride : OpenXmlCompositeElement, IExtensionChildrenParent<FormatOverride>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "fmtOvr");
@@ -9366,6 +9438,9 @@ public UInt32Value? Idx
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9868,7 +9943,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExternalData" /> <c>&lt;cx:externalData></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartData : OpenXmlCompositeElement
+    public partial class ChartData : OpenXmlCompositeElement, IExtensionChildrenParent<ChartData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "chartData");
@@ -9907,6 +9982,9 @@ public ChartData(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9954,7 +10032,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExternalData? Exte
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.PlotArea" /> <c>&lt;cx:plotArea></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Chart : OpenXmlCompositeElement
+    public partial class Chart : OpenXmlCompositeElement, IExtensionChildrenParent<Chart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "chart");
@@ -9993,6 +10071,9 @@ public Chart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10078,7 +10159,7 @@ public DocumentFormat.OpenXml.Office2016.Drawing.ChartDrawing.ExtensionList? Ext
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorMappingType : OpenXmlCompositeElement
+    public partial class ColorMappingType : OpenXmlCompositeElement, IExtensionChildrenParent<ColorMappingType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2014/chartex", "clrMapOvr");
@@ -10237,6 +10318,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.ColorSchemeIndexValues>? Followe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2016_12_diagram.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2016_12_diagram.g.cs
index eed3ec52d..dd8bbc708 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2016_12_diagram.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2016_12_diagram.g.cs
@@ -42,7 +42,7 @@ namespace DocumentFormat.OpenXml.Office2019.Drawing.Diagram12
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2016/12/diagram", "spPr");
@@ -91,6 +91,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -192,7 +195,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextListStyleType : OpenXmlCompositeElement
+    public partial class TextListStyleType : OpenXmlCompositeElement, IExtensionChildrenParent<TextListStyleType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2016/12/diagram", "lstStyle");
@@ -231,6 +234,9 @@ public TextListStyleType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2017_model3d.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2017_model3d.g.cs
index c8fc81226..bcf18bafc 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2017_model3d.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2017_model3d.g.cs
@@ -42,7 +42,7 @@ namespace DocumentFormat.OpenXml.Office2019.Drawing.Model3D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.WindowViewport" /> <c>&lt;am3d:winViewport></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Model3D : OpenXmlCompositeElement
+    public partial class Model3D : OpenXmlCompositeElement, IExtensionChildrenParent<Model3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "model3d");
@@ -107,6 +107,9 @@ public StringValue? Link
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1120,7 +1123,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.SzPositiveRatio" /> <c>&lt;am3d:sz></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OrthographicProjection : OpenXmlCompositeElement
+    public partial class OrthographicProjection : OpenXmlCompositeElement, IExtensionChildrenParent<OrthographicProjection>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "orthographic");
@@ -1159,6 +1162,9 @@ public OrthographicProjection(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1214,7 +1220,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList" /> <c>&lt;am3d:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PerspectiveProjection : OpenXmlCompositeElement
+    public partial class PerspectiveProjection : OpenXmlCompositeElement, IExtensionChildrenParent<PerspectiveProjection>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "perspective");
@@ -1263,6 +1269,9 @@ public Int32Value? Fov
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1326,7 +1335,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TintEffect" /> <c>&lt;a:tint></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Blip : OpenXmlCompositeElement
+    public partial class Blip : OpenXmlCompositeElement, IExtensionChildrenParent<Blip>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "blip");
@@ -1401,6 +1410,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlipCompressionValues>? Compress
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1737,7 +1749,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "spPr");
@@ -1786,6 +1798,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1882,7 +1897,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.PerspectiveProjection" /> <c>&lt;am3d:perspective></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Model3DCamera : OpenXmlCompositeElement
+    public partial class Model3DCamera : OpenXmlCompositeElement, IExtensionChildrenParent<Model3DCamera>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "camera");
@@ -1921,6 +1936,9 @@ public Model3DCamera(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2005,7 +2023,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.LookAtPoint3D? LookAtPo
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.Scale3D" /> <c>&lt;am3d:scale></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Model3DTransform : OpenXmlCompositeElement
+    public partial class Model3DTransform : OpenXmlCompositeElement, IExtensionChildrenParent<Model3DTransform>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "trans");
@@ -2044,6 +2062,9 @@ public Model3DTransform(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2382,7 +2403,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList" /> <c>&lt;am3d:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ObjectViewport : OpenXmlCompositeElement
+    public partial class ObjectViewport : OpenXmlCompositeElement, IExtensionChildrenParent<ObjectViewport>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "objViewport");
@@ -2431,6 +2452,9 @@ public Int64Value? ViewportSz
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2477,7 +2501,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList" /> <c>&lt;am3d:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WindowViewport : OpenXmlCompositeElement
+    public partial class WindowViewport : OpenXmlCompositeElement, IExtensionChildrenParent<WindowViewport>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "winViewport");
@@ -2516,6 +2540,9 @@ public WindowViewport(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2558,7 +2585,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.IlluminancePositiveRatio" /> <c>&lt;am3d:illuminance></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AmbientLight : OpenXmlCompositeElement
+    public partial class AmbientLight : OpenXmlCompositeElement, IExtensionChildrenParent<AmbientLight>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "ambientLight");
@@ -2607,6 +2634,9 @@ public BooleanValue? Enabled
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2682,7 +2712,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.IntensityPositiveRatio" /> <c>&lt;am3d:intensity></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PointLight : OpenXmlCompositeElement
+    public partial class PointLight : OpenXmlCompositeElement, IExtensionChildrenParent<PointLight>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "ptLight");
@@ -2741,6 +2771,9 @@ public Int64Value? Rad
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2837,7 +2870,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.IntensityPositiveRatio" /> <c>&lt;am3d:intensity></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SpotLight : OpenXmlCompositeElement
+    public partial class SpotLight : OpenXmlCompositeElement, IExtensionChildrenParent<SpotLight>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "spotLight");
@@ -2906,6 +2939,9 @@ public Int32Value? SpotAng
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3022,7 +3058,7 @@ public DocumentFormat.OpenXml.Office2019.Drawing.Model3D.OfficeArtExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Model3D.IlluminancePositiveRatio" /> <c>&lt;am3d:illuminance></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DirectionalLight : OpenXmlCompositeElement
+    public partial class DirectionalLight : OpenXmlCompositeElement, IExtensionChildrenParent<DirectionalLight>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2017/model3d", "dirLight");
@@ -3081,6 +3117,9 @@ public Int32Value? AngularRad
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation.g.cs
index 3a2ab2b08..b72c16c30 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2019.Drawing.Animation
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Animation.OfficeArtExtensionList" /> <c>&lt;aanim:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AnimationProperties : OpenXmlCompositeElement
+    public partial class AnimationProperties : OpenXmlCompositeElement, IExtensionChildrenParent<AnimationProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2018/animation", "animPr");
@@ -137,6 +137,9 @@ public StringValue? End
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation_model3d.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation_model3d.g.cs
index 476511492..b1442db7e 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation_model3d.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_animation_model3d.g.cs
@@ -30,7 +30,7 @@ namespace DocumentFormat.OpenXml.Office2019.Drawing.Animation.Model3D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Animation.Model3D.AnimationProperties" /> <c>&lt;a3danim:animPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class EmbeddedAnimation : OpenXmlCompositeElement
+    public partial class EmbeddedAnimation : OpenXmlCompositeElement, IExtensionChildrenParent<EmbeddedAnimation>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2018/animation/model3d", "embedAnim");
@@ -79,6 +79,9 @@ public UInt32Value? AnimId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -199,7 +202,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Drawing.Animation.OfficeArtExtensionList" /> <c>&lt;aanim:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AnimationProperties : OpenXmlCompositeElement
+    public partial class AnimationProperties : OpenXmlCompositeElement, IExtensionChildrenParent<AnimationProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2018/animation/model3d", "animPr");
@@ -308,6 +311,9 @@ public StringValue? End
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_sketchyshapes.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_sketchyshapes.g.cs
index d7c5dbf93..038f8e144 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_sketchyshapes.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2018_sketchyshapes.g.cs
@@ -182,7 +182,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.SketchyShapes.LineSketchSeed" /> <c>&lt;ask:seed></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LineSketchStyleProperties : OpenXmlCompositeElement
+    public partial class LineSketchStyleProperties : OpenXmlCompositeElement, IExtensionChildrenParent<LineSketchStyleProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2018/sketchyshapes", "lineSketchStyleProps");
@@ -231,6 +231,9 @@ public UInt32Value? Sd
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_livefeed.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_livefeed.g.cs
index f91b6c42f..2dd47590d 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_livefeed.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_livefeed.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2021.Drawing.Livefeed
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList" /> <c>&lt;alf:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackgroundNormalProperties : OpenXmlCompositeElement
+    public partial class BackgroundNormalProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BackgroundNormalProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "Normal");
@@ -67,6 +67,9 @@ public BackgroundNormalProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -107,7 +110,7 @@ public DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList" /> <c>&lt;alf:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackgroundRemovedProperties : OpenXmlCompositeElement
+    public partial class BackgroundRemovedProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BackgroundRemovedProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "Removed");
@@ -146,6 +149,9 @@ public BackgroundRemovedProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -186,7 +192,7 @@ public DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList" /> <c>&lt;alf:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackgroundBlurProperties : OpenXmlCompositeElement
+    public partial class BackgroundBlurProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BackgroundBlurProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "Blur");
@@ -225,6 +231,9 @@ public BackgroundBlurProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -265,7 +274,7 @@ public DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList" /> <c>&lt;alf:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackgroundCustomProperties : OpenXmlCompositeElement
+    public partial class BackgroundCustomProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BackgroundCustomProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "Custom");
@@ -304,6 +313,9 @@ public BackgroundCustomProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -345,7 +357,7 @@ public DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.OfficeArtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.LiveFeedBackgroundProperties" /> <c>&lt;alf:backgroundProps></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LiveFeedProperties : OpenXmlCompositeElement
+    public partial class LiveFeedProperties : OpenXmlCompositeElement, IExtensionChildrenParent<LiveFeedProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "liveFeedProps");
@@ -384,6 +396,9 @@ public LiveFeedProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -515,7 +530,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Drawing.Livefeed.BackgroundRemovedProperties" /> <c>&lt;alf:Removed></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LiveFeedBackgroundProperties : OpenXmlCompositeElement
+    public partial class LiveFeedBackgroundProperties : OpenXmlCompositeElement, IExtensionChildrenParent<LiveFeedBackgroundProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/livefeed", "backgroundProps");
@@ -554,6 +569,9 @@ public LiveFeedBackgroundProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_oembed.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_oembed.g.cs
index 9b802711f..f4bc6c5dd 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_oembed.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_oembed.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office.Drawing.Y2021.OEmbed
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.Y2021.OEmbed.OfficeArtExtensionList" /> <c>&lt;aoe:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OEmbedShared : OpenXmlCompositeElement
+    public partial class OEmbedShared : OpenXmlCompositeElement, IExtensionChildrenParent<OEmbedShared>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/oembed", "oembedShared");
@@ -87,6 +87,9 @@ public StringValue? Type
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_scriptlink.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_scriptlink.g.cs
index 088ede783..871e93391 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_scriptlink.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_drawing_2021_scriptlink.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office.Drawing.Y2021.ScriptLink
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Drawing.Y2021.ScriptLink.OfficeArtExtensionList" /> <c>&lt;asl:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ScriptLink : OpenXmlCompositeElement
+    public partial class ScriptLink : OpenXmlCompositeElement, IExtensionChildrenParent<ScriptLink>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/drawing/2021/scriptlink", "scriptLink");
@@ -77,6 +77,9 @@ public StringValue? Val
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2006_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2006_main.g.cs
index 065805f9f..ee0da2595 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2006_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2006_main.g.cs
@@ -54,7 +54,7 @@ namespace DocumentFormat.OpenXml.Office.Excel
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SortState" /> <c>&lt;x:sortState></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Macrosheet : OpenXmlPartRootElement
+    public partial class Macrosheet : OpenXmlPartRootElement, IExtensionChildrenParent<Macrosheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/excel/2006/main", "macrosheet");
@@ -93,6 +93,9 @@ public Macrosheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2010_spreadsheetDrawing.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2010_spreadsheetDrawing.g.cs
index b35915d8e..8edeb9930 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2010_spreadsheetDrawing.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_excel_2010_spreadsheetDrawing.g.cs
@@ -32,7 +32,7 @@ namespace DocumentFormat.OpenXml.Office2010.Excel.Drawing
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.Drawing.ExcelNonVisualContentPartShapeProperties" /> <c>&lt;xdr14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPart : OpenXmlCompositeElement
+    public partial class ContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/excel/2010/spreadsheetDrawing", "contentPart");
@@ -94,6 +94,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -190,7 +193,7 @@ public DocumentFormat.OpenXml.Office2010.Excel.Drawing.OfficeArtExtensionList? O
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/excel/2010/spreadsheetDrawing", "cNvPr");
@@ -279,6 +282,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -362,7 +368,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ContentPartLocks" /> <c>&lt;a14:cpLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement
+    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualInkContentPartProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/excel/2010/spreadsheetDrawing", "cNvContentPartPr");
@@ -411,6 +417,9 @@ public BooleanValue? IsComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2010_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2010_main.g.cs
index 30e0bd9f3..bca578dac 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2010_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2010_main.g.cs
@@ -358,7 +358,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.PowerPoint.MediaTrim" /> <c>&lt;p14:trim></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Media : OpenXmlCompositeElement
+    public partial class Media : OpenXmlCompositeElement, IExtensionChildrenParent<Media>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "media");
@@ -423,6 +423,9 @@ public StringValue? Link
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2331,7 +2334,7 @@ public DocumentFormat.OpenXml.Office2010.PowerPoint.NullEventRecord? NullEventRe
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "cNvPr");
@@ -2420,6 +2423,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2503,7 +2509,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ContentPartLocks" /> <c>&lt;a14:cpLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement
+    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualInkContentPartProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "cNvContentPartPr");
@@ -2552,6 +2558,9 @@ public BooleanValue? IsComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2616,7 +2625,7 @@ public DocumentFormat.OpenXml.Office2010.Drawing.OfficeArtExtensionList? OfficeA
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.PlaceholderShape" /> <c>&lt;p:ph></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ApplicationNonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class ApplicationNonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ApplicationNonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "nvPr");
@@ -2675,6 +2684,9 @@ public BooleanValue? UserDrawn
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3040,7 +3052,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.PowerPoint.ExtensionList" /> <c>&lt;p14:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SectionOld : OpenXmlCompositeElement
+    public partial class SectionOld : OpenXmlCompositeElement, IExtensionChildrenParent<SectionOld>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "section");
@@ -3109,6 +3121,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3273,7 +3288,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.PowerPoint.SectionSlideIdList" /> <c>&lt;p14:sldIdLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Section : OpenXmlCompositeElement
+    public partial class Section : OpenXmlCompositeElement, IExtensionChildrenParent<Section>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2010/main", "section");
@@ -3332,6 +3347,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2012_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2012_main.g.cs
index 75ac59fd7..e0eb623fb 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2012_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2012_main.g.cs
@@ -249,7 +249,7 @@ public DocumentFormat.OpenXml.Office2013.PowerPoint.ParentCommentIdentifier? Par
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.PowerPoint.ExtendedGuide" /> <c>&lt;p15:guide></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideGuideList : ExtendedGuideList
+    public partial class SlideGuideList : ExtendedGuideList, IExtensionChildrenParent<SlideGuideList>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2012/main", "sldGuideLst");
@@ -288,6 +288,9 @@ public SlideGuideList(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -316,7 +319,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.PowerPoint.ExtendedGuide" /> <c>&lt;p15:guide></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesGuideList : ExtendedGuideList
+    public partial class NotesGuideList : ExtendedGuideList, IExtensionChildrenParent<NotesGuideList>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2012/main", "notesGuideLst");
@@ -355,6 +358,9 @@ public NotesGuideList(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -383,7 +389,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.PowerPoint.ExtendedGuide" /> <c>&lt;p15:guide></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class ExtendedGuideList : OpenXmlCompositeElement
+    public abstract partial class ExtendedGuideList : OpenXmlCompositeElement, IExtensionChildrenParent<ExtendedGuideList>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -422,6 +428,9 @@ protected ExtendedGuideList(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -779,7 +788,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.PowerPoint.ExtensionList" /> <c>&lt;p15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ExtendedGuide : OpenXmlCompositeElement
+    public partial class ExtendedGuide : OpenXmlCompositeElement, IExtensionChildrenParent<ExtendedGuide>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2012/main", "guide");
@@ -868,6 +877,9 @@ public BooleanValue? IsUserDrawn
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2018_8_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2018_8_main.g.cs
index 8d0006cab..35125bdb2 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2018_8_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2018_8_main.g.cs
@@ -547,7 +547,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Comment.ExtensionList" /> <c>&lt;p188:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Author : OpenXmlCompositeElement
+    public partial class Author : OpenXmlCompositeElement, IExtensionChildrenParent<Author>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2018/8/main", "author");
@@ -636,6 +636,9 @@ public StringValue? ProviderId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -696,7 +699,7 @@ public DocumentFormat.OpenXml.Office2021.PowerPoint.Comment.ExtensionList? Exten
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Comment.CommentPropertiesExtensionList" /> <c>&lt;p188:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommentReply : OpenXmlCompositeElement
+    public partial class CommentReply : OpenXmlCompositeElement, IExtensionChildrenParent<CommentReply>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2018/8/main", "reply");
@@ -795,6 +798,9 @@ public ListValue<StringValue>? Likes
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1018,7 +1024,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Presentation.Command.SlideMonikerList" /> <c>&lt;pc:sldMkLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Comment : OpenXmlCompositeElement
+    public partial class Comment : OpenXmlCompositeElement, IExtensionChildrenParent<Comment>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2018/8/main", "cm");
@@ -1177,6 +1183,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2019_12_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2019_12_main.g.cs
index f95e38b47..f226ebe18 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2019_12_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2019_12_main.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2021.PowerPoint.Tasks
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Tasks.TaskHistory" /> <c>&lt;p1912:history></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryDetails : OpenXmlCompositeElement
+    public partial class TaskHistoryDetails : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryDetails>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2019/12/main", "taskHistoryDetails");
@@ -78,6 +78,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -394,7 +397,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Tasks.CommentAnchor" /> <c>&lt;p1912:comment></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskAnchor : OpenXmlCompositeElement
+    public partial class TaskAnchor : OpenXmlCompositeElement, IExtensionChildrenParent<TaskAnchor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2019/12/main", "anchr");
@@ -433,6 +436,9 @@ public TaskAnchor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -860,7 +866,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Tasks.TaskUnknownRecord" /> <c>&lt;p1912:unknown></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryEvent : OpenXmlCompositeElement
+    public partial class TaskHistoryEvent : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryEvent>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2019/12/main", "event");
@@ -919,6 +925,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2020_02_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2020_02_main.g.cs
index 28d644ada..37e9c4e39 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2020_02_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2020_02_main.g.cs
@@ -95,7 +95,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.PowerPoint.Designer.DesignerTagList" /> <c>&lt;p202:designTagLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DesignerDrawingProps : OpenXmlCompositeElement
+    public partial class DesignerDrawingProps : OpenXmlCompositeElement, IExtensionChildrenParent<DesignerDrawingProps>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2020/02/main", "designPr");
@@ -144,6 +144,9 @@ public BooleanValue? EdtDesignElem
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2021_06_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2021_06_main.g.cs
index aa2ceb404..44b8b6781 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2021_06_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2021_06_main.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office.PowerPoint.Y2021.M06.Main
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2021.M06.Main.TaskHistory" /> <c>&lt;p216:history></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryDetails : OpenXmlCompositeElement
+    public partial class TaskHistoryDetails : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryDetails>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2021/06/main", "taskHistoryDetails");
@@ -78,6 +78,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -394,7 +397,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2021.M06.Main.CommentAnchor" /> <c>&lt;p216:comment></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskAnchor : OpenXmlCompositeElement
+    public partial class TaskAnchor : OpenXmlCompositeElement, IExtensionChildrenParent<TaskAnchor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2021/06/main", "anchr");
@@ -433,6 +436,9 @@ public TaskAnchor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -860,7 +866,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2021.M06.Main.TaskUnknownRecord" /> <c>&lt;p216:unknown></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryEvent : OpenXmlCompositeElement
+    public partial class TaskHistoryEvent : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryEvent>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2021/06/main", "event");
@@ -919,6 +925,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_03_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_03_main.g.cs
index e9772f8b6..2c39aa124 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_03_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_03_main.g.cs
@@ -166,7 +166,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M03.Main.ExtensionList" /> <c>&lt;p223:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ReactionInstance : OpenXmlCompositeElement
+    public partial class ReactionInstance : OpenXmlCompositeElement, IExtensionChildrenParent<ReactionInstance>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2022/03/main", "instance");
@@ -225,6 +225,9 @@ public StringValue? AuthorId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_08_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_08_main.g.cs
index 2d8f61265..09c5fed79 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_08_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_powerpoint_2022_08_main.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M08.Main
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M08.Main.TaskHistory" /> <c>&lt;p228:history></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskDetails : OpenXmlCompositeElement
+    public partial class TaskDetails : OpenXmlCompositeElement, IExtensionChildrenParent<TaskDetails>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2022/08/main", "taskDetails");
@@ -88,6 +88,9 @@ public BooleanValue? Inactive
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -370,7 +373,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M08.Main.CommentAnchor" /> <c>&lt;p228:comment></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskAnchor : OpenXmlCompositeElement
+    public partial class TaskAnchor : OpenXmlCompositeElement, IExtensionChildrenParent<TaskAnchor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2022/08/main", "anchr");
@@ -409,6 +412,9 @@ public TaskAnchor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -787,7 +793,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M08.Main.TaskUnknownRecord" /> <c>&lt;p228:unknown></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryEvent : OpenXmlCompositeElement
+    public partial class TaskHistoryEvent : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryEvent>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/powerpoint/2022/08/main", "event");
@@ -846,6 +852,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2009_9_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2009_9_main.g.cs
index e95a6c285..0fb0f4ace 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2009_9_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2009_9_main.g.cs
@@ -408,7 +408,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.IgnoredError" /> <c>&lt;x14:ignoredError></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class IgnoredErrors : OpenXmlCompositeElement
+    public partial class IgnoredErrors : OpenXmlCompositeElement, IExtensionChildrenParent<IgnoredErrors>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "ignoredErrors");
@@ -447,6 +447,9 @@ public IgnoredErrors(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2357,7 +2360,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.ExtensionList" /> <c>&lt;x14:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DatastoreItem : OpenXmlPartRootElement
+    public partial class DatastoreItem : OpenXmlPartRootElement, IExtensionChildrenParent<DatastoreItem>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "datastoreItem");
@@ -2406,6 +2409,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2484,7 +2490,7 @@ public CustomDataPropertiesPart? CustomDataPropertiesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.ListItems" /> <c>&lt;x14:itemLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FormControlProperties : OpenXmlPartRootElement
+    public partial class FormControlProperties : OpenXmlPartRootElement, IExtensionChildrenParent<FormControlProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "formControlPr");
@@ -2833,6 +2839,9 @@ public BooleanValue? PasswordEdit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3070,7 +3079,7 @@ public SlicersPart? SlicersPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.SlicerCachePivotTables" /> <c>&lt;x14:pivotTables></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlicerCacheDefinition : OpenXmlPartRootElement
+    public partial class SlicerCacheDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<SlicerCacheDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "slicerCacheDefinition");
@@ -3129,6 +3138,9 @@ public StringValue? SourceName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3241,7 +3253,7 @@ public SlicerCachePart? SlicerCachePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Excel.ReferenceSequence" /> <c>&lt;xne:sqref></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormatting : OpenXmlCompositeElement
+    public partial class ConditionalFormatting : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormatting>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "conditionalFormatting");
@@ -3290,6 +3302,9 @@ public BooleanValue? Pivot
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3328,7 +3343,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.IconSet" /> <c>&lt;x14:iconSet></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormattingRule : OpenXmlCompositeElement
+    public partial class ConditionalFormattingRule : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormattingRule>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "cfRule");
@@ -3507,6 +3522,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6463,7 +6481,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DifferentialType : OpenXmlCompositeElement
+    public partial class DifferentialType : OpenXmlCompositeElement, IExtensionChildrenParent<DifferentialType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "dxf");
@@ -6502,6 +6520,9 @@ public DifferentialType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6633,7 +6654,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Excel.Formula" /> <c>&lt;xne:f></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormattingValueObject : OpenXmlCompositeElement
+    public partial class ConditionalFormattingValueObject : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormattingValueObject>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "cfvo");
@@ -6692,6 +6713,9 @@ public BooleanValue? GreaterThanOrEqual
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7104,7 +7128,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.TupleItems" /> <c>&lt;x14:tupleItems></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotEdit : OpenXmlCompositeElement
+    public partial class PivotEdit : OpenXmlCompositeElement, IExtensionChildrenParent<PivotEdit>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "pivotEdit");
@@ -7143,6 +7167,9 @@ public PivotEdit(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7390,7 +7417,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotAreaReferences" /> <c>&lt;x:references></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotArea : OpenXmlCompositeElement
+    public partial class PivotArea : OpenXmlCompositeElement, IExtensionChildrenParent<PivotArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "pivotArea");
@@ -7549,6 +7576,9 @@ public UInt32Value? FieldPosition
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7619,7 +7649,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.TupleItems" /> <c>&lt;x14:tupleItems></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotChange : OpenXmlCompositeElement
+    public partial class PivotChange : OpenXmlCompositeElement, IExtensionChildrenParent<PivotChange>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "pivotChange");
@@ -7678,6 +7708,9 @@ public StringValue? WeightExpression
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8012,7 +8045,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.PivotAreas" /> <c>&lt;x14:pivotAreas></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormat : OpenXmlCompositeElement
+    public partial class ConditionalFormat : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "conditionalFormat");
@@ -8091,6 +8124,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8838,7 +8874,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.ListItem" /> <c>&lt;x14:item></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ListItems : OpenXmlCompositeElement
+    public partial class ListItems : OpenXmlCompositeElement, IExtensionChildrenParent<ListItems>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "itemLst");
@@ -8877,6 +8913,9 @@ public ListItems(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8906,7 +8945,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.ExtensionList" /> <c>&lt;x14:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Slicer : OpenXmlCompositeElement
+    public partial class Slicer : OpenXmlCompositeElement, IExtensionChildrenParent<Slicer>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "slicer");
@@ -9045,6 +9084,9 @@ public UInt32Value? RowHeight
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9112,7 +9154,7 @@ public DocumentFormat.OpenXml.Office2010.Excel.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.OlapSlicerCacheSelections" /> <c>&lt;x14:selections></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OlapSlicerCache : OpenXmlCompositeElement
+    public partial class OlapSlicerCache : OpenXmlCompositeElement, IExtensionChildrenParent<OlapSlicerCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "olap");
@@ -9161,6 +9203,9 @@ public UInt32Value? PivotCacheId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9237,7 +9282,7 @@ public DocumentFormat.OpenXml.Office2010.Excel.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.TabularSlicerCacheItems" /> <c>&lt;x14:items></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TabularSlicerCache : OpenXmlCompositeElement
+    public partial class TabularSlicerCache : OpenXmlCompositeElement, IExtensionChildrenParent<TabularSlicerCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main", "tabular");
@@ -9326,6 +9371,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2010.Excel.SlicerCacheCrossFilterV
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2010_11_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2010_11_main.g.cs
index f16744961..30d7c4bb1 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2010_11_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2010_11_main.g.cs
@@ -1016,7 +1016,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.FieldListActiveTabTopLevelEntity" /> <c>&lt;x15:activeTabTopLevelEntity></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotTableUISettings : OpenXmlCompositeElement
+    public partial class PivotTableUISettings : OpenXmlCompositeElement, IExtensionChildrenParent<PivotTableUISettings>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "pivotTableUISettings");
@@ -1075,6 +1075,9 @@ public BooleanValue? RelNeededHidden
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1370,7 +1373,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ModelTables" /> <c>&lt;x15:modelTables></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataModel : OpenXmlCompositeElement
+    public partial class DataModel : OpenXmlCompositeElement, IExtensionChildrenParent<DataModel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "dataModel");
@@ -1419,6 +1422,9 @@ public ByteValue? MinVersionLoad
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1851,7 +1857,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableSlicerCache : OpenXmlCompositeElement
+    public partial class TableSlicerCache : OpenXmlCompositeElement, IExtensionChildrenParent<TableSlicerCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "tableSlicerCache");
@@ -1940,6 +1946,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2010.Excel.SlicerCacheCrossFilterV
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2140,7 +2149,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.SurveyQuestions" /> <c>&lt;x15:questions></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Survey : OpenXmlCompositeElement
+    public partial class Survey : OpenXmlCompositeElement, IExtensionChildrenParent<Survey>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "survey");
@@ -2219,6 +2228,9 @@ public StringValue? Description
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2430,7 +2442,7 @@ public TimeLinePart? TimeLinePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.TimelineState" /> <c>&lt;x15:state></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TimelineCacheDefinition : OpenXmlPartRootElement
+    public partial class TimelineCacheDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<TimelineCacheDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "timelineCacheDefinition");
@@ -2489,6 +2501,9 @@ public StringValue? SourceName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4716,7 +4731,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SurveyPrSurveyElementPr : OpenXmlSurveyElementPrElement
+    public partial class SurveyPrSurveyElementPr : OpenXmlSurveyElementPrElement, IExtensionChildrenParent<SurveyPrSurveyElementPr>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "surveyPr");
@@ -4755,6 +4770,9 @@ public SurveyPrSurveyElementPr(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4781,7 +4799,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TitlePrSurveyElementPr : OpenXmlSurveyElementPrElement
+    public partial class TitlePrSurveyElementPr : OpenXmlSurveyElementPrElement, IExtensionChildrenParent<TitlePrSurveyElementPr>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "titlePr");
@@ -4820,6 +4838,9 @@ public TitlePrSurveyElementPr(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4846,7 +4867,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DescriptionPrSurveyElementPr : OpenXmlSurveyElementPrElement
+    public partial class DescriptionPrSurveyElementPr : OpenXmlSurveyElementPrElement, IExtensionChildrenParent<DescriptionPrSurveyElementPr>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "descriptionPr");
@@ -4885,6 +4906,9 @@ public DescriptionPrSurveyElementPr(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4911,7 +4935,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QuestionsPrSurveyElementPr : OpenXmlSurveyElementPrElement
+    public partial class QuestionsPrSurveyElementPr : OpenXmlSurveyElementPrElement, IExtensionChildrenParent<QuestionsPrSurveyElementPr>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "questionsPr");
@@ -4950,6 +4974,9 @@ public QuestionsPrSurveyElementPr(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4976,7 +5003,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QuestionPrSurveyElementPr : OpenXmlSurveyElementPrElement
+    public partial class QuestionPrSurveyElementPr : OpenXmlSurveyElementPrElement, IExtensionChildrenParent<QuestionPrSurveyElementPr>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "questionPr");
@@ -5015,6 +5042,9 @@ public QuestionPrSurveyElementPr(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5041,7 +5071,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class OpenXmlSurveyElementPrElement : OpenXmlCompositeElement
+    public abstract partial class OpenXmlSurveyElementPrElement : OpenXmlCompositeElement, IExtensionChildrenParent<OpenXmlSurveyElementPrElement>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -5160,6 +5190,9 @@ public EnumValue<DocumentFormat.OpenXml.Office2013.Excel.SurveyPosition>? Positi
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5283,7 +5316,7 @@ public DocumentFormat.OpenXml.Office2013.Excel.QuestionsPrSurveyElementPr? Quest
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.QuestionPrSurveyElementPr" /> <c>&lt;x15:questionPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SurveyQuestion : OpenXmlCompositeElement
+    public partial class SurveyQuestion : OpenXmlCompositeElement, IExtensionChildrenParent<SurveyQuestion>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "question");
@@ -5412,6 +5445,9 @@ public StringValue? RowSource
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5480,7 +5516,7 @@ public DocumentFormat.OpenXml.Office2013.Excel.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.ExtensionList" /> <c>&lt;x15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Timeline : OpenXmlCompositeElement
+    public partial class Timeline : OpenXmlCompositeElement, IExtensionChildrenParent<Timeline>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "timeline");
@@ -5629,6 +5665,9 @@ public StringValue? Style
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5873,7 +5912,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SortState" /> <c>&lt;x:sortState></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AutoFilter : OpenXmlCompositeElement
+    public partial class AutoFilter : OpenXmlCompositeElement, IExtensionChildrenParent<AutoFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "autoFilter");
@@ -5922,6 +5961,9 @@ public StringValue? Reference
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6024,7 +6066,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Excel.BoundsTimelineRange" /> <c>&lt;x15:bounds></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TimelineState : OpenXmlCompositeElement
+    public partial class TimelineState : OpenXmlCompositeElement, IExtensionChildrenParent<TimelineState>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2010/11/main", "state");
@@ -6143,6 +6185,9 @@ public StringValue? FilterPivotName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2014_revision.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2014_revision.g.cs
index 57906b797..6215fd0b9 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2014_revision.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2014_revision.g.cs
@@ -263,7 +263,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DifferentialFormatType : OpenXmlCompositeElement
+    public partial class DifferentialFormatType : OpenXmlCompositeElement, IExtensionChildrenParent<DifferentialFormatType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "dxf");
@@ -302,6 +302,9 @@ public DifferentialFormatType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1569,7 +1572,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Excel.ExtensionList" /> <c>&lt;xr:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevExFormatting : OpenXmlCompositeElement
+    public partial class RevExFormatting : OpenXmlCompositeElement, IExtensionChildrenParent<RevExFormatting>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "xrrf");
@@ -1798,6 +1801,9 @@ public BooleanValue? ApplyProtection
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1894,7 +1900,7 @@ public DocumentFormat.OpenXml.Office2016.Excel.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2016.Excel.FormulaFormula" /> <c>&lt;xr:formula></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevExDefinedName : OpenXmlCompositeElement
+    public partial class RevExDefinedName : OpenXmlCompositeElement, IExtensionChildrenParent<RevExDefinedName>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "xrrDefName");
@@ -2093,6 +2099,9 @@ public StringValue? Comment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5831,7 +5840,7 @@ public DocumentFormat.OpenXml.Office2010.Excel.Sparklines? Sparklines
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Comments : OpenXmlCompositeElement
+    public partial class Comments : OpenXmlCompositeElement, IExtensionChildrenParent<Comments>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "comments");
@@ -5870,6 +5879,9 @@ public Comments(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5942,7 +5954,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SortState" /> <c>&lt;x:sortState></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AutoFilter : OpenXmlCompositeElement
+    public partial class AutoFilter : OpenXmlCompositeElement, IExtensionChildrenParent<AutoFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "autoFilter");
@@ -5991,6 +6003,9 @@ public StringValue? Reference
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6040,7 +6055,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.RowItems" /> <c>&lt;x:rowItems></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class pivotTableDefinition : OpenXmlCompositeElement
+    public partial class pivotTableDefinition : OpenXmlCompositeElement, IExtensionChildrenParent<pivotTableDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2014/revision", "pivotTableDefinition");
@@ -6759,6 +6774,9 @@ public BooleanValue? CustomListSort
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_dynamicarray.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_dynamicarray.g.cs
index 494a1e78c..22cd553bc 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_dynamicarray.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_dynamicarray.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office2019.Excel.DynamicArray
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.DynamicArray.ExtensionList" /> <c>&lt;xda:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DynamicArrayProperties : OpenXmlCompositeElement
+    public partial class DynamicArrayProperties : OpenXmlCompositeElement, IExtensionChildrenParent<DynamicArrayProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/dynamicarray", "dynamicArrayProperties");
@@ -87,6 +87,9 @@ public BooleanValue? FCollapsed
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata.g.cs
index 346026b02..0388fc1f2 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata.g.cs
@@ -75,7 +75,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData.RichValue" /> <c>&lt;xlrd:rv></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueData : OpenXmlPartRootElement
+    public partial class RichValueData : OpenXmlPartRootElement, IExtensionChildrenParent<RichValueData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata", "rvData");
@@ -124,6 +124,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -190,7 +193,7 @@ public RdRichValuePart? RdRichValuePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData.RichValueStructure" /> <c>&lt;xlrd:s></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueStructures : OpenXmlPartRootElement
+    public partial class RichValueStructures : OpenXmlPartRootElement, IExtensionChildrenParent<RichValueStructures>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata", "rvStructures");
@@ -239,6 +242,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata2.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata2.g.cs
index 4528db988..f5ad6c75b 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata2.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2017_richdata2.g.cs
@@ -32,7 +32,7 @@ namespace DocumentFormat.OpenXml.Office2019.Excel.RichData2
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichTop10" /> <c>&lt;xlrd2:top10></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichFilterColumn : OpenXmlCompositeElement
+    public partial class RichFilterColumn : OpenXmlCompositeElement, IExtensionChildrenParent<RichFilterColumn>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "filterColumn");
@@ -71,6 +71,9 @@ public RichFilterColumn(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -421,7 +424,7 @@ public RdSupportingPropertyBagPart? RdSupportingPropertyBagPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.SupportingPropertyBagStructure" /> <c>&lt;xlrd2:s></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SupportingPropertyBagStructures : OpenXmlPartRootElement
+    public partial class SupportingPropertyBagStructures : OpenXmlPartRootElement, IExtensionChildrenParent<SupportingPropertyBagStructures>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "spbStructures");
@@ -470,6 +473,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -536,7 +542,7 @@ public RdSupportingPropertyBagStructurePart? RdSupportingPropertyBagStructurePar
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.Array" /> <c>&lt;xlrd2:a></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ArrayData : OpenXmlPartRootElement
+    public partial class ArrayData : OpenXmlPartRootElement, IExtensionChildrenParent<ArrayData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "arrayData");
@@ -585,6 +591,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -653,7 +662,7 @@ public RdArrayPart? RdArrayPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichStyles" /> <c>&lt;xlrd2:richStyles></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichStylesheet : OpenXmlPartRootElement
+    public partial class RichStylesheet : OpenXmlPartRootElement, IExtensionChildrenParent<RichStylesheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "richStyleSheet");
@@ -692,6 +701,9 @@ public RichStylesheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -810,7 +822,7 @@ public RichStylesPart? RichStylesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichValueTypes" /> <c>&lt;xlrd2:types></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueTypesInfo : OpenXmlPartRootElement
+    public partial class RichValueTypesInfo : OpenXmlPartRootElement, IExtensionChildrenParent<RichValueTypesInfo>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "rvTypesInfo");
@@ -849,6 +861,9 @@ public RichValueTypesInfo(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -952,7 +967,7 @@ public RdRichValueTypesPart? RdRichValueTypesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichFilter" /> <c>&lt;xlrd2:filter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichFilters : OpenXmlCompositeElement
+    public partial class RichFilters : OpenXmlCompositeElement, IExtensionChildrenParent<RichFilters>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "filters");
@@ -991,6 +1006,9 @@ public RichFilters(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1113,7 +1131,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.CustomRichFilter" /> <c>&lt;xlrd2:customFilter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CustomRichFilters : OpenXmlCompositeElement
+    public partial class CustomRichFilters : OpenXmlCompositeElement, IExtensionChildrenParent<CustomRichFilters>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "customFilters");
@@ -1162,6 +1180,9 @@ public BooleanValue? And
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1643,7 +1664,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.SupportingPropertyBagArray" /> <c>&lt;xlrd2:a></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SupportingPropertyBagArrayData : OpenXmlCompositeElement
+    public partial class SupportingPropertyBagArrayData : OpenXmlCompositeElement, IExtensionChildrenParent<SupportingPropertyBagArrayData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "spbArrays");
@@ -1692,6 +1713,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1727,7 +1751,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.SupportingPropertyBag" /> <c>&lt;xlrd2:spb></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SupportingPropertyBagData : OpenXmlCompositeElement
+    public partial class SupportingPropertyBagData : OpenXmlCompositeElement, IExtensionChildrenParent<SupportingPropertyBagData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "spbData");
@@ -1776,6 +1800,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2751,7 +2778,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichValueTypeKeyFlags" /> <c>&lt;xlrd2:keyFlags></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueGlobalType : OpenXmlCompositeElement
+    public partial class RichValueGlobalType : OpenXmlCompositeElement, IExtensionChildrenParent<RichValueGlobalType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "global");
@@ -2790,6 +2817,9 @@ public RichValueGlobalType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2912,7 +2942,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.RichData2.RichValueTypeKeyFlags" /> <c>&lt;xlrd2:keyFlags></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueType : OpenXmlCompositeElement
+    public partial class RichValueType : OpenXmlCompositeElement, IExtensionChildrenParent<RichValueType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2017/richdata2", "type");
@@ -2961,6 +2991,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2018_threadedcomments.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2018_threadedcomments.g.cs
index 5896dc8fe..b580e062f 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2018_threadedcomments.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2018_threadedcomments.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2019.Excel.ThreadedComments
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.ThreadedComments.Person" /> <c>&lt;xltc:person></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PersonList : OpenXmlPartRootElement
+    public partial class PersonList : OpenXmlPartRootElement, IExtensionChildrenParent<PersonList>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2018/threadedcomments", "personList");
@@ -68,6 +68,9 @@ public PersonList(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -129,7 +132,7 @@ public WorkbookPersonPart? WorkbookPersonPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.ThreadedComments.ThreadedComment" /> <c>&lt;xltc:threadedComment></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ThreadedComments : OpenXmlPartRootElement
+    public partial class ThreadedComments : OpenXmlPartRootElement, IExtensionChildrenParent<ThreadedComments>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2018/threadedcomments", "ThreadedComments");
@@ -168,6 +171,9 @@ public ThreadedComments(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -228,7 +234,7 @@ public WorksheetThreadedCommentsPart? WorksheetThreadedCommentsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.ThreadedComments.ExtensionList" /> <c>&lt;xltc:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Person : OpenXmlCompositeElement
+    public partial class Person : OpenXmlCompositeElement, IExtensionChildrenParent<Person>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2018/threadedcomments", "person");
@@ -307,6 +313,9 @@ public StringValue? ProviderId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -433,7 +442,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2019.Excel.ThreadedComments.ThreadedCommentMentions" /> <c>&lt;xltc:mentions></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ThreadedComment : OpenXmlCompositeElement
+    public partial class ThreadedComment : OpenXmlCompositeElement, IExtensionChildrenParent<ThreadedComment>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2018/threadedcomments", "threadedComment");
@@ -532,6 +541,9 @@ public BooleanValue? Done
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2019_namedsheetviews.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2019_namedsheetviews.g.cs
index cd5f73c58..d4cea7353 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2019_namedsheetviews.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2019_namedsheetviews.g.cs
@@ -31,7 +31,7 @@ namespace DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.NamedSheetView" /> <c>&lt;xnsv:namedSheetView></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NamedSheetViews : OpenXmlPartRootElement
+    public partial class NamedSheetViews : OpenXmlPartRootElement, IExtensionChildrenParent<NamedSheetViews>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "namedSheetViews");
@@ -70,6 +70,9 @@ public NamedSheetViews(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -131,7 +134,7 @@ public NamedSheetViewsPart? NamedSheetViewsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.NsvFilter" /> <c>&lt;xnsv:nsvFilter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NamedSheetView : OpenXmlCompositeElement
+    public partial class NamedSheetView : OpenXmlCompositeElement, IExtensionChildrenParent<NamedSheetView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "namedSheetView");
@@ -190,6 +193,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -303,7 +309,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.SortRules" /> <c>&lt;xnsv:sortRules></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NsvFilter : OpenXmlCompositeElement
+    public partial class NsvFilter : OpenXmlCompositeElement, IExtensionChildrenParent<NsvFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "nsvFilter");
@@ -372,6 +378,9 @@ public UInt32Value? TableId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -413,7 +422,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.FilterColumn" /> <c>&lt;xnsv:filter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColumnFilter : OpenXmlCompositeElement
+    public partial class ColumnFilter : OpenXmlCompositeElement, IExtensionChildrenParent<ColumnFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "columnFilter");
@@ -472,6 +481,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -526,7 +538,7 @@ public DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.DifferentialForma
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.NamedSheetViews.SortRule" /> <c>&lt;xnsv:sortRule></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SortRules : OpenXmlCompositeElement
+    public partial class SortRules : OpenXmlCompositeElement, IExtensionChildrenParent<SortRules>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "sortRules");
@@ -585,6 +597,9 @@ public BooleanValue? CaseSensitive
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -623,7 +638,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DifferentialFormatType : OpenXmlCompositeElement
+    public partial class DifferentialFormatType : OpenXmlCompositeElement, IExtensionChildrenParent<DifferentialFormatType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "dxf");
@@ -662,6 +677,9 @@ public DifferentialFormatType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -800,7 +818,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.IconFilter" /> <c>&lt;x14:iconFilter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FilterColumn : OpenXmlCompositeElement
+    public partial class FilterColumn : OpenXmlCompositeElement, IExtensionChildrenParent<FilterColumn>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2019/namedsheetviews", "filter");
@@ -869,6 +887,9 @@ public BooleanValue? ShowButton
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_richdatawebimage.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_richdatawebimage.g.cs
index 791037ad1..0b8b35f38 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_richdatawebimage.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_richdatawebimage.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2021.Excel.RichDataWebImage
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.RichDataWebImage.WebImageSupportingRichData" /> <c>&lt;xlrdwi:webImageSrd></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebImagesSupportingRichData : OpenXmlPartRootElement
+    public partial class WebImagesSupportingRichData : OpenXmlPartRootElement, IExtensionChildrenParent<WebImagesSupportingRichData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2020/richdatawebimage", "webImagesSrd");
@@ -68,6 +68,9 @@ public WebImagesSupportingRichData(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_threadedcomments2.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_threadedcomments2.g.cs
index aa7b8954a..4186df2e6 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_threadedcomments2.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2020_threadedcomments2.g.cs
@@ -73,7 +73,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Excel.ThreadedComments2.ExtensionList" /> <c>&lt;xltc2:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommentHyperlink : OpenXmlCompositeElement
+    public partial class CommentHyperlink : OpenXmlCompositeElement, IExtensionChildrenParent<CommentHyperlink>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2020/threadedcomments2", "hyperlink");
@@ -142,6 +142,9 @@ public StringValue? Url
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_featurepropertybag.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_featurepropertybag.g.cs
index 4561e2db2..e6cb868f2 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_featurepropertybag.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_featurepropertybag.g.cs
@@ -30,7 +30,7 @@ namespace DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag.FeaturePropertyBag" /> <c>&lt;xfpb:bag></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FeaturePropertyBags : OpenXmlPartRootElement
+    public partial class FeaturePropertyBags : OpenXmlPartRootElement, IExtensionChildrenParent<FeaturePropertyBags>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2022/featurepropertybag", "FeaturePropertyBags");
@@ -79,6 +79,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -145,7 +148,7 @@ public FeaturePropertyBagsPart? FeaturePropertyBagsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag.FeaturePropertyBag" /> <c>&lt;xfpb:bag></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FpbsFeaturePropertyBags : OpenXmlFeaturePropertyBagsElement
+    public partial class FpbsFeaturePropertyBags : OpenXmlFeaturePropertyBagsElement, IExtensionChildrenParent<FpbsFeaturePropertyBags>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2022/featurepropertybag", "fpbs");
@@ -184,6 +187,9 @@ public FpbsFeaturePropertyBags(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -214,7 +220,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag.FeaturePropertyBag" /> <c>&lt;xfpb:bag></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class OpenXmlFeaturePropertyBagsElement : OpenXmlCompositeElement
+    public abstract partial class OpenXmlFeaturePropertyBagsElement : OpenXmlCompositeElement, IExtensionChildrenParent<OpenXmlFeaturePropertyBagsElement>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -263,6 +269,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1160,7 +1169,7 @@ public DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag.DifferentialFormat
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Y2022.FeaturePropertyBag.ExtensionList" /> <c>&lt;xfpb:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BagExtensions : OpenXmlCompositeElement
+    public partial class BagExtensions : OpenXmlCompositeElement, IExtensionChildrenParent<BagExtensions>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2022/featurepropertybag", "bagExt");
@@ -1199,6 +1208,9 @@ public BagExtensions(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1899,7 +1911,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DifferentialFormatType : OpenXmlCompositeElement
+    public partial class DifferentialFormatType : OpenXmlCompositeElement, IExtensionChildrenParent<DifferentialFormatType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2022/featurepropertybag", "dxf");
@@ -1938,6 +1950,9 @@ public DifferentialFormatType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_richvaluerel.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_richvaluerel.g.cs
index c19b6ae0c..51b296c38 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_richvaluerel.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2022_richvaluerel.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office.Y2022.RichValueRel
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.Y2022.RichValueRel.RichValueRelRelationship" /> <c>&lt;xlrvrel:rel></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RichValueRels : OpenXmlCompositeElement
+    public partial class RichValueRels : OpenXmlCompositeElement, IExtensionChildrenParent<RichValueRels>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2022/richvaluerel", "richValueRels");
@@ -68,6 +68,9 @@ public RichValueRels(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2023_msForms.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2023_msForms.g.cs
index 4db9ea193..ded0595fd 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2023_msForms.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_spreadsheetml_2023_msForms.g.cs
@@ -28,7 +28,7 @@ namespace DocumentFormat.OpenXml.Office.SpreadSheetML.Y2023.MsForms
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.SpreadSheetML.Y2023.MsForms.ExtensionList" /> <c>&lt;xlmsforms:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Question : OpenXmlCompositeElement
+    public partial class Question : OpenXmlCompositeElement, IExtensionChildrenParent<Question>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2023/msForms", "question");
@@ -77,6 +77,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -123,7 +126,7 @@ public DocumentFormat.OpenXml.Office.SpreadSheetML.Y2023.MsForms.ExtensionList?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office.SpreadSheetML.Y2023.MsForms.SyncedQuestionId" /> <c>&lt;xlmsforms:syncedQuestionId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MsForm : OpenXmlCompositeElement
+    public partial class MsForm : OpenXmlCompositeElement, IExtensionChildrenParent<MsForm>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/spreadsheetml/2023/msForms", "msForm");
@@ -202,6 +205,9 @@ public StringValue? LatestEventMarker
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_tasks_2019_documenttasks.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_tasks_2019_documenttasks.g.cs
index 15bfbf7ba..16b5059b5 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_tasks_2019_documenttasks.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_tasks_2019_documenttasks.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2021.DocumentTasks
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.DocumentTasks.Task" /> <c>&lt;t:Task></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Tasks : OpenXmlPartRootElement
+    public partial class Tasks : OpenXmlPartRootElement, IExtensionChildrenParent<Tasks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/tasks/2019/documenttasks", "Tasks");
@@ -68,6 +68,9 @@ public Tasks(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -130,7 +133,7 @@ public DocumentTasksPart? DocumentTasksPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.DocumentTasks.TaskHistory" /> <c>&lt;t:History></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Task : OpenXmlCompositeElement
+    public partial class Task : OpenXmlCompositeElement, IExtensionChildrenParent<Task>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/tasks/2019/documenttasks", "Task");
@@ -179,6 +182,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -322,7 +328,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.DocumentTasks.CommentAnchor" /> <c>&lt;t:Comment></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskAnchor : OpenXmlCompositeElement
+    public partial class TaskAnchor : OpenXmlCompositeElement, IExtensionChildrenParent<TaskAnchor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/tasks/2019/documenttasks", "Anchor");
@@ -361,6 +367,9 @@ public TaskAnchor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -495,7 +504,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.DocumentTasks.UnassignTaskUser" /> <c>&lt;t:Unassign></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TaskHistoryEvent : OpenXmlCompositeElement
+    public partial class TaskHistoryEvent : OpenXmlCompositeElement, IExtensionChildrenParent<TaskHistoryEvent>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/tasks/2019/documenttasks", "Event");
@@ -554,6 +563,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_thememl_2012_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_thememl_2012_main.g.cs
index 52591bfe2..813549594 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_thememl_2012_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_thememl_2012_main.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2013.Theme
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Theme.OfficeArtExtensionList" /> <c>&lt;thm15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ThemeFamily : OpenXmlCompositeElement
+    public partial class ThemeFamily : OpenXmlCompositeElement, IExtensionChildrenParent<ThemeFamily>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/thememl/2012/main", "themeFamily");
@@ -98,6 +98,9 @@ public StringValue? Vid
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -226,7 +229,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.Theme.OfficeArtExtensionList" /> <c>&lt;thm15:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ThemeVariant : OpenXmlCompositeElement
+    public partial class ThemeVariant : OpenXmlCompositeElement, IExtensionChildrenParent<ThemeVariant>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/thememl/2012/main", "themeVariant");
@@ -318,6 +321,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_taskpanes_2010_11.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_taskpanes_2010_11.g.cs
index 105cf08eb..78fd8c433 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_taskpanes_2010_11.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_taskpanes_2010_11.g.cs
@@ -250,7 +250,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.WebExtentionPane.WebExtensionPartReference" /> <c>&lt;wetp:webextensionref></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebExtensionTaskpane : OpenXmlCompositeElement
+    public partial class WebExtensionTaskpane : OpenXmlCompositeElement, IExtensionChildrenParent<WebExtensionTaskpane>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/webextensions/taskpanes/2010/11", "taskpane");
@@ -339,6 +339,9 @@ public BooleanValue? Locked
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_webextension_2010_11.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_webextension_2010_11.g.cs
index 10ad55126..a958cf60e 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_webextension_2010_11.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_webextensions_webextension_2010_11.g.cs
@@ -34,7 +34,7 @@ namespace DocumentFormat.OpenXml.Office2013.WebExtension
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.WebExtension.WebExtensionReferenceList" /> <c>&lt;we:alternateReferences></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebExtension : OpenXmlPartRootElement
+    public partial class WebExtension : OpenXmlPartRootElement, IExtensionChildrenParent<WebExtension>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/webextensions/webextension/2010/11", "webextension");
@@ -93,6 +93,9 @@ public BooleanValue? Frozen
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -427,7 +430,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.WebExtension.OfficeArtExtensionList" /> <c>&lt;we:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebExtensionBinding : OpenXmlCompositeElement
+    public partial class WebExtensionBinding : OpenXmlCompositeElement, IExtensionChildrenParent<WebExtensionBinding>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/webextensions/webextension/2010/11", "binding");
@@ -496,6 +499,9 @@ public StringValue? AppReference
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -549,7 +555,7 @@ public DocumentFormat.OpenXml.Office2013.WebExtension.OfficeArtExtensionList? Of
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.WebExtension.OfficeArtExtensionList" /> <c>&lt;we:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebExtensionStoreReference : OpenXmlCompositeElement
+    public partial class WebExtensionStoreReference : OpenXmlCompositeElement, IExtensionChildrenParent<WebExtensionStoreReference>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/webextensions/webextension/2010/11", "reference");
@@ -628,6 +634,9 @@ public StringValue? StoreType
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -895,7 +904,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TintEffect" /> <c>&lt;a:tint></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Snapshot : OpenXmlCompositeElement
+    public partial class Snapshot : OpenXmlCompositeElement, IExtensionChildrenParent<Snapshot>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/webextensions/webextension/2010/11", "snapshot");
@@ -970,6 +979,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlipCompressionValues>? Compress
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordml.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordml.g.cs
index 515ccba15..731c0cbdd 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordml.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordml.g.cs
@@ -3846,7 +3846,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.WordNonVisualContentPartShapeProperties" /> <c>&lt;w14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPart : OpenXmlCompositeElement
+    public partial class ContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordml", "contentPart");
@@ -3911,6 +3911,9 @@ public StringValue? RelationshipId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5428,7 +5431,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordml", "cNvPr");
@@ -5517,6 +5520,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5600,7 +5606,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.ContentPartLocks" /> <c>&lt;a14:cpLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement
+    public partial class NonVisualInkContentPartProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualInkContentPartProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordml", "cNvContentPartPr");
@@ -5649,6 +5655,9 @@ public BooleanValue? IsComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingCanvas.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingCanvas.g.cs
index 18057e65d..e2277066d 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingCanvas.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingCanvas.g.cs
@@ -39,7 +39,7 @@ namespace DocumentFormat.OpenXml.Office2010.Word.DrawingCanvas
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.WordprocessingShape" /> <c>&lt;wps:wsp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WordprocessingCanvas : OpenXmlCompositeElement
+    public partial class WordprocessingCanvas : OpenXmlCompositeElement, IExtensionChildrenParent<WordprocessingCanvas>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas", "wpc");
@@ -78,6 +78,9 @@ public WordprocessingCanvas(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -342,7 +345,7 @@ public DocumentFormat.OpenXml.Drawing.Outline? Outline
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingGroup.Transform2D" /> <c>&lt;wpg:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicFrameType : OpenXmlCompositeElement
+    public partial class GraphicFrameType : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicFrameType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas", "graphicFrame");
@@ -381,6 +384,9 @@ public GraphicFrameType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingGroup.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingGroup.g.cs
index ad15ef7b2..66a17473e 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingGroup.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingGroup.g.cs
@@ -39,7 +39,7 @@ namespace DocumentFormat.OpenXml.Office2010.Word.DrawingGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.WordprocessingShape" /> <c>&lt;wps:wsp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WordprocessingGroup : WordprocessingGroupType
+    public partial class WordprocessingGroup : WordprocessingGroupType, IExtensionChildrenParent<WordprocessingGroup>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "wgp");
@@ -78,6 +78,9 @@ public WordprocessingGroup(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -123,7 +126,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.WordprocessingShape" /> <c>&lt;wps:wsp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShape : WordprocessingGroupType
+    public partial class GroupShape : WordprocessingGroupType, IExtensionChildrenParent<GroupShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "grpSp");
@@ -162,6 +165,9 @@ public GroupShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -207,7 +213,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.WordprocessingShape" /> <c>&lt;wps:wsp></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class WordprocessingGroupType : OpenXmlCompositeElement
+    public abstract partial class WordprocessingGroupType : OpenXmlCompositeElement, IExtensionChildrenParent<WordprocessingGroupType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -246,6 +252,9 @@ protected WordprocessingGroupType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -313,7 +322,7 @@ public DocumentFormat.OpenXml.Office2010.Word.DrawingGroup.GroupShapeProperties?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "cNvPr");
@@ -402,6 +411,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -485,7 +497,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "cNvFrPr");
@@ -524,6 +536,9 @@ public NonVisualGraphicFrameProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -781,7 +796,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupDrawingShapeProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupDrawingShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupDrawingShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "cNvGrpSpPr");
@@ -820,6 +835,9 @@ public NonVisualGroupDrawingShapeProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -885,7 +903,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionLi
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "grpSpPr");
@@ -934,6 +952,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1015,7 +1036,7 @@ public DocumentFormat.OpenXml.Drawing.TransformGroup? TransformGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingGroup.Transform2D" /> <c>&lt;wpg:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicFrame : OpenXmlCompositeElement
+    public partial class GraphicFrame : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicFrame>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingGroup", "graphicFrame");
@@ -1054,6 +1075,9 @@ public GraphicFrame(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingShape.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingShape.g.cs
index 167c67c26..79ee41026 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingShape.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2010_wordprocessingShape.g.cs
@@ -37,7 +37,7 @@ namespace DocumentFormat.OpenXml.Office2010.Word.DrawingShape
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.TextBoxInfo2" /> <c>&lt;wps:txbx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WordprocessingShape : OpenXmlCompositeElement
+    public partial class WordprocessingShape : OpenXmlCompositeElement, IExtensionChildrenParent<WordprocessingShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "wsp");
@@ -86,6 +86,9 @@ public BooleanValue? NormalEastAsianFlow
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -224,7 +227,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "cNvPr");
@@ -313,6 +316,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -396,7 +402,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingShapeProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "cNvSpPr");
@@ -445,6 +451,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -505,7 +514,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualConnectorProperties : OpenXmlCompositeElement
+    public partial class NonVisualConnectorProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualConnectorProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "cNvCnPr");
@@ -544,6 +553,9 @@ public NonVisualConnectorProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -643,7 +655,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "spPr");
@@ -692,6 +704,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -911,7 +926,7 @@ public DocumentFormat.OpenXml.Drawing.FontReference? FontReference
     ///   <item><description><see cref="DocumentFormat.OpenXml.Wordprocessing.TextBoxContent" /> <c>&lt;w:txbxContent></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextBoxInfo2 : OpenXmlCompositeElement
+    public partial class TextBoxInfo2 : OpenXmlCompositeElement, IExtensionChildrenParent<TextBoxInfo2>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "txbx");
@@ -960,6 +975,9 @@ public UInt16Value? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1017,7 +1035,7 @@ public DocumentFormat.OpenXml.Office2010.Word.DrawingShape.OfficeArtExtensionLis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Word.DrawingShape.OfficeArtExtensionList" /> <c>&lt;wps:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LinkedTextBox : OpenXmlCompositeElement
+    public partial class LinkedTextBox : OpenXmlCompositeElement, IExtensionChildrenParent<LinkedTextBox>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "linkedTxbx");
@@ -1076,6 +1094,9 @@ public UInt16Value? Sequence
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1132,7 +1153,7 @@ public DocumentFormat.OpenXml.Office2010.Word.DrawingShape.OfficeArtExtensionLis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeAutoFit" /> <c>&lt;a:spAutoFit></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextBodyProperties : OpenXmlCompositeElement
+    public partial class TextBodyProperties : OpenXmlCompositeElement, IExtensionChildrenParent<TextBodyProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2010/wordprocessingShape", "bodyPr");
@@ -1361,6 +1382,9 @@ public BooleanValue? CompatibleLineSpacing
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2018_wordml_cex.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2018_wordml_cex.g.cs
index 1fa1a8a6a..a9222f75d 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2018_wordml_cex.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_microsoft_com_office_word_2018_wordml_cex.g.cs
@@ -29,7 +29,7 @@ namespace DocumentFormat.OpenXml.Office2021.Word.CommentsExt
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Word.CommentsExt.ExtensionList" /> <c>&lt;w16cex:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommentsExtensible : OpenXmlPartRootElement
+    public partial class CommentsExtensible : OpenXmlPartRootElement, IExtensionChildrenParent<CommentsExtensible>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2018/wordml/cex", "commentsExtensible");
@@ -68,6 +68,9 @@ public CommentsExtensible(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -128,7 +131,7 @@ public WordCommentsExtensiblePart? WordCommentsExtensiblePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2021.Word.CommentsExt.ExtensionList" /> <c>&lt;w16cex:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommentExtensible : OpenXmlCompositeElement
+    public partial class CommentExtensible : OpenXmlCompositeElement, IExtensionChildrenParent<CommentExtensible>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.microsoft.com/office/word/2018/wordml/cex", "commentExtensible");
@@ -206,6 +209,9 @@ public OnOffValue? IntelligentPlaceholder
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chart.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chart.g.cs
index 8c29c40e6..492bbe555 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chart.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chart.g.cs
@@ -103,7 +103,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartShapeProperties : OpenXmlCompositeElement
+    public partial class ChartShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ChartShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "spPr");
@@ -152,6 +152,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1873,7 +1876,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ManualLayout" /> <c>&lt;c:manualLayout></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Layout : OpenXmlCompositeElement
+    public partial class Layout : OpenXmlCompositeElement, IExtensionChildrenParent<Layout>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "layout");
@@ -1912,6 +1915,9 @@ public Layout(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2974,7 +2980,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LineChartSeries : OpenXmlCompositeElement
+    public partial class LineChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<LineChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -3013,6 +3019,9 @@ public LineChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3164,7 +3173,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Separator" /> <c>&lt;c:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabels : OpenXmlCompositeElement
+    public partial class DataLabels : OpenXmlCompositeElement, IExtensionChildrenParent<DataLabels>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dLbls");
@@ -3203,6 +3212,9 @@ public DataLabels(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3374,7 +3386,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BarChartSeries : OpenXmlCompositeElement
+    public partial class BarChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<BarChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -3413,6 +3425,9 @@ public BarChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3560,7 +3575,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AreaChartSeries : OpenXmlCompositeElement
+    public partial class AreaChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<AreaChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -3599,6 +3614,9 @@ public AreaChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3728,7 +3746,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.PictureOptions? PictureOptions
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Explosion" /> <c>&lt;c:explosion></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PieChartSeries : OpenXmlCompositeElement
+    public partial class PieChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<PieChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -3767,6 +3785,9 @@ public PieChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3905,7 +3926,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Explosion? Explosion
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SurfaceChartSeries : OpenXmlCompositeElement
+    public partial class SurfaceChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<SurfaceChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -3944,6 +3965,9 @@ public SurfaceChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4178,7 +4202,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Orientation" /> <c>&lt;c:orientation></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Scaling : OpenXmlCompositeElement
+    public partial class Scaling : OpenXmlCompositeElement, IExtensionChildrenParent<Scaling>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "scaling");
@@ -4217,6 +4241,9 @@ public Scaling(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4366,7 +4393,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ChartText" /> <c>&lt;c:tx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Title : OpenXmlCompositeElement
+    public partial class Title : OpenXmlCompositeElement, IExtensionChildrenParent<Title>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "title");
@@ -4405,6 +4432,9 @@ public Title(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5155,7 +5185,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.Charts.Style" /> <c>&lt;c14:style></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartSpace : OpenXmlPartRootElement
+    public partial class ChartSpace : OpenXmlPartRootElement, IExtensionChildrenParent<ChartSpace>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "chartSpace");
@@ -5194,6 +5224,9 @@ public ChartSpace(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6194,7 +6227,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Formula" /> <c>&lt;c:f></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NumberReference : OpenXmlCompositeElement
+    public partial class NumberReference : OpenXmlCompositeElement, IExtensionChildrenParent<NumberReference>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "numRef");
@@ -6233,6 +6266,9 @@ public NumberReference(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6305,7 +6341,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.NumRefExtensionList? NumRefExtensio
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.FormatCode" /> <c>&lt;c:formatCode></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NumberLiteral : NumberDataType
+    public partial class NumberLiteral : NumberDataType, IExtensionChildrenParent<NumberLiteral>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "numLit");
@@ -6344,6 +6380,9 @@ public NumberLiteral(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6375,7 +6414,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.FormatCode" /> <c>&lt;c:formatCode></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NumberingCache : NumberDataType
+    public partial class NumberingCache : NumberDataType, IExtensionChildrenParent<NumberingCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "numCache");
@@ -6414,6 +6453,9 @@ public NumberingCache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6445,7 +6487,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.FormatCode" /> <c>&lt;c:formatCode></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class NumberDataType : OpenXmlCompositeElement
+    public abstract partial class NumberDataType : OpenXmlCompositeElement, IExtensionChildrenParent<NumberDataType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -6484,6 +6526,9 @@ protected NumberDataType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6598,7 +6643,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Formula" /> <c>&lt;c:f></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MultiLevelStringReference : OpenXmlCompositeElement
+    public partial class MultiLevelStringReference : OpenXmlCompositeElement, IExtensionChildrenParent<MultiLevelStringReference>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "multiLvlStrRef");
@@ -6637,6 +6682,9 @@ public MultiLevelStringReference(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6708,7 +6756,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.MultiLvlStrRefExtensionList? MultiL
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Formula" /> <c>&lt;c:f></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StringReference : OpenXmlCompositeElement
+    public partial class StringReference : OpenXmlCompositeElement, IExtensionChildrenParent<StringReference>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "strRef");
@@ -6747,6 +6795,9 @@ public StringReference(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6818,7 +6869,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.StrRefExtensionList? StrRefExtensio
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StringLiteral : StringDataType
+    public partial class StringLiteral : StringDataType, IExtensionChildrenParent<StringLiteral>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "strLit");
@@ -6857,6 +6908,9 @@ public StringLiteral(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6886,7 +6940,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StringCache : StringDataType
+    public partial class StringCache : StringDataType, IExtensionChildrenParent<StringCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "strCache");
@@ -6925,6 +6979,9 @@ public StringCache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6954,7 +7011,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class StringDataType : OpenXmlCompositeElement
+    public abstract partial class StringDataType : OpenXmlCompositeElement, IExtensionChildrenParent<StringDataType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -6993,6 +7050,9 @@ protected StringDataType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7235,7 +7295,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.LayoutTarget" /> <c>&lt;c:layoutTarget></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ManualLayout : OpenXmlCompositeElement
+    public partial class ManualLayout : OpenXmlCompositeElement, IExtensionChildrenParent<ManualLayout>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "manualLayout");
@@ -7274,6 +7334,9 @@ public ManualLayout(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7766,7 +7829,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Symbol" /> <c>&lt;c:symbol></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Marker : OpenXmlCompositeElement
+    public partial class Marker : OpenXmlCompositeElement, IExtensionChildrenParent<Marker>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "marker");
@@ -7805,6 +7868,9 @@ public Marker(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8171,7 +8237,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ChartText" /> <c>&lt;c:tx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TrendlineLabel : OpenXmlCompositeElement
+    public partial class TrendlineLabel : OpenXmlCompositeElement, IExtensionChildrenParent<TrendlineLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "trendlineLbl");
@@ -8210,6 +8276,9 @@ public TrendlineLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -9833,7 +9902,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Index" /> <c>&lt;c:idx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotFormat : OpenXmlCompositeElement
+    public partial class PivotFormat : OpenXmlCompositeElement, IExtensionChildrenParent<PivotFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "pivotFmt");
@@ -9872,6 +9941,9 @@ public PivotFormat(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10016,7 +10088,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Index" /> <c>&lt;c:idx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LegendEntry : OpenXmlCompositeElement
+    public partial class LegendEntry : OpenXmlCompositeElement, IExtensionChildrenParent<LegendEntry>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "legendEntry");
@@ -10055,6 +10127,9 @@ public LegendEntry(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10568,7 +10643,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "spPr");
@@ -10617,6 +10692,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10722,7 +10800,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Separator" /> <c>&lt;c:separator></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataLabel : OpenXmlCompositeElement
+    public partial class DataLabel : OpenXmlCompositeElement, IExtensionChildrenParent<DataLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dLbl");
@@ -10761,6 +10839,9 @@ public DataLabel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10851,7 +10932,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Index? Index
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AreaChart : OpenXmlCompositeElement
+    public partial class AreaChart : OpenXmlCompositeElement, IExtensionChildrenParent<AreaChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "areaChart");
@@ -10890,6 +10971,9 @@ public AreaChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10967,7 +11051,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Area3DChart : OpenXmlCompositeElement
+    public partial class Area3DChart : OpenXmlCompositeElement, IExtensionChildrenParent<Area3DChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "area3DChart");
@@ -11006,6 +11090,9 @@ public Area3DChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11088,7 +11175,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.UpDownBars" /> <c>&lt;c:upDownBars></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LineChart : OpenXmlCompositeElement
+    public partial class LineChart : OpenXmlCompositeElement, IExtensionChildrenParent<LineChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "lineChart");
@@ -11127,6 +11214,9 @@ public LineChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11212,7 +11302,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Line3DChart : OpenXmlCompositeElement
+    public partial class Line3DChart : OpenXmlCompositeElement, IExtensionChildrenParent<Line3DChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "line3DChart");
@@ -11251,6 +11341,9 @@ public Line3DChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11329,7 +11422,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.UpDownBars" /> <c>&lt;c:upDownBars></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StockChart : OpenXmlCompositeElement
+    public partial class StockChart : OpenXmlCompositeElement, IExtensionChildrenParent<StockChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "stockChart");
@@ -11368,6 +11461,9 @@ public StockChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11411,7 +11507,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RadarChart : OpenXmlCompositeElement
+    public partial class RadarChart : OpenXmlCompositeElement, IExtensionChildrenParent<RadarChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "radarChart");
@@ -11450,6 +11546,9 @@ public RadarChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11517,7 +11616,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ScatterChart : OpenXmlCompositeElement
+    public partial class ScatterChart : OpenXmlCompositeElement, IExtensionChildrenParent<ScatterChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "scatterChart");
@@ -11556,6 +11655,9 @@ public ScatterChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11622,7 +11724,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PieChartSeries" /> <c>&lt;c:ser></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PieChart : OpenXmlCompositeElement
+    public partial class PieChart : OpenXmlCompositeElement, IExtensionChildrenParent<PieChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "pieChart");
@@ -11661,6 +11763,9 @@ public PieChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11717,7 +11822,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PieChartSeries" /> <c>&lt;c:ser></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Pie3DChart : OpenXmlCompositeElement
+    public partial class Pie3DChart : OpenXmlCompositeElement, IExtensionChildrenParent<Pie3DChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "pie3DChart");
@@ -11756,6 +11861,9 @@ public Pie3DChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11812,7 +11920,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PieChartSeries" /> <c>&lt;c:ser></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DoughnutChart : OpenXmlCompositeElement
+    public partial class DoughnutChart : OpenXmlCompositeElement, IExtensionChildrenParent<DoughnutChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "doughnutChart");
@@ -11851,6 +11959,9 @@ public DoughnutChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11915,7 +12026,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BarChart : OpenXmlCompositeElement
+    public partial class BarChart : OpenXmlCompositeElement, IExtensionChildrenParent<BarChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "barChart");
@@ -11954,6 +12065,9 @@ public BarChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12052,7 +12166,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Bar3DChart : OpenXmlCompositeElement
+    public partial class Bar3DChart : OpenXmlCompositeElement, IExtensionChildrenParent<Bar3DChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "bar3DChart");
@@ -12091,6 +12205,9 @@ public Bar3DChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12190,7 +12307,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.SplitType" /> <c>&lt;c:splitType></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OfPieChart : OpenXmlCompositeElement
+    public partial class OfPieChart : OpenXmlCompositeElement, IExtensionChildrenParent<OfPieChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ofPieChart");
@@ -12229,6 +12346,9 @@ public OfPieChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12311,7 +12431,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SurfaceChart : OpenXmlCompositeElement
+    public partial class SurfaceChart : OpenXmlCompositeElement, IExtensionChildrenParent<SurfaceChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "surfaceChart");
@@ -12350,6 +12470,9 @@ public SurfaceChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12408,7 +12531,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Wireframe? Wireframe
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Surface3DChart : OpenXmlCompositeElement
+    public partial class Surface3DChart : OpenXmlCompositeElement, IExtensionChildrenParent<Surface3DChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "surface3DChart");
@@ -12447,6 +12570,9 @@ public Surface3DChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12517,7 +12643,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.AxisId" /> <c>&lt;c:axId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BubbleChart : OpenXmlCompositeElement
+    public partial class BubbleChart : OpenXmlCompositeElement, IExtensionChildrenParent<BubbleChart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "bubbleChart");
@@ -12556,6 +12682,9 @@ public BubbleChart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12631,7 +12760,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.VaryColors? VaryColors
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ValAxExtensionList" /> <c>&lt;c:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ValueAxis : OpenXmlCompositeElement
+    public partial class ValueAxis : OpenXmlCompositeElement, IExtensionChildrenParent<ValueAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "valAx");
@@ -12670,6 +12799,9 @@ public ValueAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12949,7 +13081,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis? CrossingAxis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis" /> <c>&lt;c:crossAx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CategoryAxis : OpenXmlCompositeElement
+    public partial class CategoryAxis : OpenXmlCompositeElement, IExtensionChildrenParent<CategoryAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "catAx");
@@ -12988,6 +13120,9 @@ public CategoryAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13272,7 +13407,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis? CrossingAxis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis" /> <c>&lt;c:crossAx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DateAxis : OpenXmlCompositeElement
+    public partial class DateAxis : OpenXmlCompositeElement, IExtensionChildrenParent<DateAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dateAx");
@@ -13311,6 +13446,9 @@ public DateAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13592,7 +13730,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis? CrossingAxis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis" /> <c>&lt;c:crossAx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SeriesAxis : OpenXmlCompositeElement
+    public partial class SeriesAxis : OpenXmlCompositeElement, IExtensionChildrenParent<SeriesAxis>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "serAx");
@@ -13631,6 +13769,9 @@ public SeriesAxis(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13890,7 +14031,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.CrossingAxis? CrossingAxis
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ExtensionList" /> <c>&lt;c:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataTable : OpenXmlCompositeElement
+    public partial class DataTable : OpenXmlCompositeElement, IExtensionChildrenParent<DataTable>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dTable");
@@ -13929,6 +14070,9 @@ public DataTable(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16214,7 +16358,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.DownBars" /> <c>&lt;c:downBars></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class UpDownBars : OpenXmlCompositeElement
+    public partial class UpDownBars : OpenXmlCompositeElement, IExtensionChildrenParent<UpDownBars>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "upDownBars");
@@ -16253,6 +16397,9 @@ public UpDownBars(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16729,7 +16876,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PointCount" /> <c>&lt;c:ptCount></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MultiLevelStringCache : OpenXmlCompositeElement
+    public partial class MultiLevelStringCache : OpenXmlCompositeElement, IExtensionChildrenParent<MultiLevelStringCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "multiLvlStrCache");
@@ -16768,6 +16915,9 @@ public MultiLevelStringCache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17125,7 +17275,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ScatterChartSeries : OpenXmlCompositeElement
+    public partial class ScatterChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<ScatterChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -17164,6 +17314,9 @@ public ScatterChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17405,7 +17558,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RadarChartSeries : OpenXmlCompositeElement
+    public partial class RadarChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<RadarChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -17444,6 +17597,9 @@ public RadarChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18000,7 +18156,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Order" /> <c>&lt;c:order></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BubbleChartSeries : OpenXmlCompositeElement
+    public partial class BubbleChartSeries : OpenXmlCompositeElement, IExtensionChildrenParent<BubbleChartSeries>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "ser");
@@ -18039,6 +18195,9 @@ public BubbleChartSeries(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19124,7 +19283,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ExtensionList" /> <c>&lt;c:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DisplayUnits : OpenXmlCompositeElement
+    public partial class DisplayUnits : OpenXmlCompositeElement, IExtensionChildrenParent<DisplayUnits>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dispUnits");
@@ -19163,6 +19322,9 @@ public DisplayUnits(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19353,7 +19515,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorMapOverride : OpenXmlCompositeElement
+    public partial class ColorMapOverride : OpenXmlCompositeElement, IExtensionChildrenParent<ColorMapOverride>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "clrMapOvr");
@@ -19512,6 +19674,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.ColorSchemeIndexValues>? Followe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19614,7 +19779,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.PivotTableName" /> <c>&lt;c:name></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotSource : OpenXmlCompositeElement
+    public partial class PivotSource : OpenXmlCompositeElement, IExtensionChildrenParent<PivotSource>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "pivotSource");
@@ -19653,6 +19818,9 @@ public PivotSource(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19876,7 +20044,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.UserInterface? UserInterface
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.View3D" /> <c>&lt;c:view3D></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Chart : OpenXmlCompositeElement
+    public partial class Chart : OpenXmlCompositeElement, IExtensionChildrenParent<Chart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "chart");
@@ -19915,6 +20083,9 @@ public Chart(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20680,7 +20851,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Explosion" /> <c>&lt;c:explosion></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataPoint : OpenXmlCompositeElement
+    public partial class DataPoint : OpenXmlCompositeElement, IExtensionChildrenParent<DataPoint>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "dPt");
@@ -20719,6 +20890,9 @@ public DataPoint(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20874,7 +21048,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.TrendlineName" /> <c>&lt;c:name></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Trendline : OpenXmlCompositeElement
+    public partial class Trendline : OpenXmlCompositeElement, IExtensionChildrenParent<Trendline>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "trendline");
@@ -20913,6 +21087,9 @@ public Trendline(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21125,7 +21302,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Minus" /> <c>&lt;c:minus></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ErrorBars : OpenXmlCompositeElement
+    public partial class ErrorBars : OpenXmlCompositeElement, IExtensionChildrenParent<ErrorBars>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "errBars");
@@ -21164,6 +21341,9 @@ public ErrorBars(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23073,7 +23253,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.RotateY" /> <c>&lt;c:rotY></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class View3D : OpenXmlCompositeElement
+    public partial class View3D : OpenXmlCompositeElement, IExtensionChildrenParent<View3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "view3D");
@@ -23112,6 +23292,9 @@ public View3D(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23244,7 +23427,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Thickness" /> <c>&lt;c:thickness></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Floor : SurfaceType
+    public partial class Floor : SurfaceType, IExtensionChildrenParent<Floor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "floor");
@@ -23283,6 +23466,9 @@ public Floor(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23314,7 +23500,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Thickness" /> <c>&lt;c:thickness></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SideWall : SurfaceType
+    public partial class SideWall : SurfaceType, IExtensionChildrenParent<SideWall>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "sideWall");
@@ -23353,6 +23539,9 @@ public SideWall(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23384,7 +23573,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Thickness" /> <c>&lt;c:thickness></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackWall : SurfaceType
+    public partial class BackWall : SurfaceType, IExtensionChildrenParent<BackWall>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "backWall");
@@ -23423,6 +23612,9 @@ public BackWall(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23454,7 +23646,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.Thickness" /> <c>&lt;c:thickness></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class SurfaceType : OpenXmlCompositeElement
+    public abstract partial class SurfaceType : OpenXmlCompositeElement, IExtensionChildrenParent<SurfaceType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -23493,6 +23685,9 @@ protected SurfaceType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23589,7 +23784,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.ValueAxis" /> <c>&lt;c:valAx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlotArea : OpenXmlCompositeElement
+    public partial class PlotArea : OpenXmlCompositeElement, IExtensionChildrenParent<PlotArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "plotArea");
@@ -23628,6 +23823,9 @@ public PlotArea(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23725,7 +23923,7 @@ public DocumentFormat.OpenXml.Drawing.Charts.Layout? Layout
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Charts.LegendPosition" /> <c>&lt;c:legendPos></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Legend : OpenXmlCompositeElement
+    public partial class Legend : OpenXmlCompositeElement, IExtensionChildrenParent<Legend>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chart", "legend");
@@ -23764,6 +23962,9 @@ public Legend(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chartDrawing.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chartDrawing.g.cs
index b62458915..daa3ec209 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chartDrawing.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_chartDrawing.g.cs
@@ -979,7 +979,7 @@ public DocumentFormat.OpenXml.Drawing.ChartDrawing.Style? Style
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvPr");
@@ -1068,6 +1068,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1151,7 +1154,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvSpPr");
@@ -1200,6 +1203,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1364,7 +1370,7 @@ public DocumentFormat.OpenXml.Drawing.ChartDrawing.NonVisualShapeDrawingProperti
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "spPr");
@@ -1413,6 +1419,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1729,7 +1738,7 @@ public DocumentFormat.OpenXml.Drawing.ListStyle? ListStyle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualConnectionShapeProperties : OpenXmlCompositeElement
+    public partial class NonVisualConnectionShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualConnectionShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvCxnSpPr");
@@ -1768,6 +1777,9 @@ public NonVisualConnectionShapeProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1947,7 +1959,7 @@ public DocumentFormat.OpenXml.Drawing.ChartDrawing.NonVisualConnectionShapePrope
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.PictureLocks" /> <c>&lt;a:picLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualPictureDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvPicPr");
@@ -1996,6 +2008,9 @@ public BooleanValue? PreferRelativeResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2276,7 +2291,7 @@ public DocumentFormat.OpenXml.Drawing.SourceRectangle? SourceRectangle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvGraphicFramePr");
@@ -2315,6 +2330,9 @@ public NonVisualGraphicFrameDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2592,7 +2610,7 @@ public DocumentFormat.OpenXml.Drawing.Extents? Extents
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "cNvGrpSpPr");
@@ -2631,6 +2649,9 @@ public NonVisualGroupShapeDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3155,7 +3176,7 @@ public DocumentFormat.OpenXml.Drawing.ChartDrawing.NonVisualGroupShapeDrawingPro
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/chartDrawing", "grpSpPr");
@@ -3204,6 +3225,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_diagram.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_diagram.g.cs
index 906a9bf9c..6bb3f6295 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_diagram.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_diagram.g.cs
@@ -34,7 +34,7 @@ namespace DocumentFormat.OpenXml.Drawing.Diagrams
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ColorTransformStyleLabel" /> <c>&lt;dgm:styleLbl></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorsDefinition : OpenXmlPartRootElement
+    public partial class ColorsDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<ColorsDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "colorsDef");
@@ -93,6 +93,9 @@ public StringValue? MinVersion
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -165,7 +168,7 @@ public DiagramColorsPart? DiagramColorsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ColorDefinitionTitle" /> <c>&lt;dgm:title></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorsDefinitionHeader : OpenXmlCompositeElement
+    public partial class ColorsDefinitionHeader : OpenXmlCompositeElement, IExtensionChildrenParent<ColorsDefinitionHeader>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "colorsDefHdr");
@@ -234,6 +237,9 @@ public Int32Value? ResourceId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -342,7 +348,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.PointList" /> <c>&lt;dgm:ptLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataModelRoot : OpenXmlPartRootElement
+    public partial class DataModelRoot : OpenXmlPartRootElement, IExtensionChildrenParent<DataModelRoot>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "dataModel");
@@ -381,6 +387,9 @@ public DataModelRoot(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -518,7 +527,7 @@ public DiagramDataPart? DiagramDataPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ColorData" /> <c>&lt;dgm:clrData></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LayoutDefinition : OpenXmlPartRootElement
+    public partial class LayoutDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<LayoutDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "layoutDef");
@@ -587,6 +596,9 @@ public StringValue? DefaultStyle
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -665,7 +677,7 @@ public DiagramLayoutDefinitionPart? DiagramLayoutDefinitionPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Title" /> <c>&lt;dgm:title></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LayoutDefinitionHeader : OpenXmlCompositeElement
+    public partial class LayoutDefinitionHeader : OpenXmlCompositeElement, IExtensionChildrenParent<LayoutDefinitionHeader>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "layoutDefHdr");
@@ -744,6 +756,9 @@ public Int32Value? ResourceId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -958,7 +973,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.StyleLabel" /> <c>&lt;dgm:styleLbl></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StyleDefinition : OpenXmlPartRootElement
+    public partial class StyleDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<StyleDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "styleDef");
@@ -1017,6 +1032,9 @@ public StringValue? MinVersion
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1090,7 +1108,7 @@ public DiagramStylePart? DiagramStylePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.StyleDefinitionTitle" /> <c>&lt;dgm:title></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StyleDefinitionHeader : OpenXmlCompositeElement
+    public partial class StyleDefinitionHeader : OpenXmlCompositeElement, IExtensionChildrenParent<StyleDefinitionHeader>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "styleDefHdr");
@@ -1159,6 +1177,9 @@ public Int32Value? ResourceId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2153,7 +2174,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.TextEffectColorList" /> <c>&lt;dgm:txEffectClrLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorTransformStyleLabel : OpenXmlCompositeElement
+    public partial class ColorTransformStyleLabel : OpenXmlCompositeElement, IExtensionChildrenParent<ColorTransformStyleLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "styleLbl");
@@ -2202,6 +2223,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2339,7 +2363,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.PropertySet" /> <c>&lt;dgm:prSet></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Point : OpenXmlCompositeElement
+    public partial class Point : OpenXmlCompositeElement, IExtensionChildrenParent<Point>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "pt");
@@ -2408,6 +2432,9 @@ public StringValue? ConnectionId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2514,7 +2541,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.PtExtensionList? PtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList" /> <c>&lt;dgm:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Connection : OpenXmlCompositeElement
+    public partial class Connection : OpenXmlCompositeElement, IExtensionChildrenParent<Connection>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "cxn");
@@ -2643,6 +2670,9 @@ public StringValue? PresentationId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2741,7 +2771,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList" /> <c>&lt;dgm:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Constraint : OpenXmlCompositeElement
+    public partial class Constraint : OpenXmlCompositeElement, IExtensionChildrenParent<Constraint>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "constr");
@@ -2890,6 +2920,9 @@ public DoubleValue? Fact
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2963,7 +2996,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList" /> <c>&lt;dgm:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Rule : OpenXmlCompositeElement
+    public partial class Rule : OpenXmlCompositeElement, IExtensionChildrenParent<Rule>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "rule");
@@ -3072,6 +3105,9 @@ public DoubleValue? Max
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3353,7 +3389,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Parameter" /> <c>&lt;dgm:param></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Algorithm : OpenXmlCompositeElement
+    public partial class Algorithm : OpenXmlCompositeElement, IExtensionChildrenParent<Algorithm>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "alg");
@@ -3412,6 +3448,9 @@ public UInt32Value? Revision
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3448,7 +3487,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.AdjustList" /> <c>&lt;dgm:adjLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape : OpenXmlCompositeElement
+    public partial class Shape : OpenXmlCompositeElement, IExtensionChildrenParent<Shape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "shape");
@@ -3560,6 +3599,9 @@ public BooleanValue? BlipPlaceholder
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3631,7 +3673,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.ExtensionList" /> <c>&lt;dgm:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PresentationOf : OpenXmlCompositeElement
+    public partial class PresentationOf : OpenXmlCompositeElement, IExtensionChildrenParent<PresentationOf>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "presOf");
@@ -3730,6 +3772,9 @@ public ListValue<Int32Value>? Step
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4264,7 +4309,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.ResizeHandles? ResizeHandles
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Shape" /> <c>&lt;dgm:shape></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ForEach : OpenXmlCompositeElement
+    public partial class ForEach : OpenXmlCompositeElement, IExtensionChildrenParent<ForEach>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "forEach");
@@ -4383,6 +4428,9 @@ public ListValue<Int32Value>? Step
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4444,7 +4492,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Shape" /> <c>&lt;dgm:shape></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LayoutNode : OpenXmlCompositeElement
+    public partial class LayoutNode : OpenXmlCompositeElement, IExtensionChildrenParent<LayoutNode>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "layoutNode");
@@ -4523,6 +4571,9 @@ public StringValue? MoveWith
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4665,7 +4716,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Shape" /> <c>&lt;dgm:shape></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DiagramChooseIf : OpenXmlCompositeElement
+    public partial class DiagramChooseIf : OpenXmlCompositeElement, IExtensionChildrenParent<DiagramChooseIf>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "if");
@@ -4814,6 +4865,9 @@ public StringValue? Val
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4904,7 +4958,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.Shape" /> <c>&lt;dgm:shape></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DiagramChooseElse : OpenXmlCompositeElement
+    public partial class DiagramChooseElse : OpenXmlCompositeElement, IExtensionChildrenParent<DiagramChooseElse>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "else");
@@ -4953,6 +5007,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5002,7 +5059,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.PointList" /> <c>&lt;dgm:ptLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataModel : OpenXmlCompositeElement
+    public partial class DataModel : OpenXmlCompositeElement, IExtensionChildrenParent<DataModel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "dataModel");
@@ -5041,6 +5098,9 @@ public DataModel(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5965,7 +6025,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Scene3D : OpenXmlCompositeElement
+    public partial class Scene3D : OpenXmlCompositeElement, IExtensionChildrenParent<Scene3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "scene3d");
@@ -6004,6 +6064,9 @@ public Scene3D(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6092,7 +6155,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape3D : OpenXmlCompositeElement
+    public partial class Shape3D : OpenXmlCompositeElement, IExtensionChildrenParent<Shape3D>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "sp3d");
@@ -6171,6 +6234,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PresetMaterialTypeValues>? Prese
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -6568,7 +6634,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Diagrams.TextProperties" /> <c>&lt;dgm:txPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class StyleLabel : OpenXmlCompositeElement
+    public partial class StyleLabel : OpenXmlCompositeElement, IExtensionChildrenParent<StyleLabel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "styleLbl");
@@ -6617,6 +6683,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7528,7 +7597,7 @@ public DocumentFormat.OpenXml.Drawing.Diagrams.Style? Style
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/diagram", "spPr");
@@ -7577,6 +7646,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_lockedCanvas.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_lockedCanvas.g.cs
index 563d4b86a..b6a01f538 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_lockedCanvas.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_lockedCanvas.g.cs
@@ -38,7 +38,7 @@ namespace DocumentFormat.OpenXml.Drawing.LockedCanvas
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.GvmlContentPart" /> <c>&lt;a14:contentPart></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LockedCanvas : OpenXmlCompositeElement
+    public partial class LockedCanvas : OpenXmlCompositeElement, IExtensionChildrenParent<LockedCanvas>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/lockedCanvas", "lockedCanvas");
@@ -77,6 +77,9 @@ public LockedCanvas(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_main.g.cs
index 1c2d45a59..a086ece0d 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_main.g.cs
@@ -47,7 +47,7 @@ namespace DocumentFormat.OpenXml.Drawing
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AudioFromCD : OpenXmlCompositeElement
+    public partial class AudioFromCD : OpenXmlCompositeElement, IExtensionChildrenParent<AudioFromCD>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "audioCd");
@@ -86,6 +86,9 @@ public AudioFromCD(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -281,7 +284,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AudioFromFile : OpenXmlCompositeElement
+    public partial class AudioFromFile : OpenXmlCompositeElement, IExtensionChildrenParent<AudioFromFile>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "audioFile");
@@ -333,6 +336,9 @@ public StringValue? Link
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -377,7 +383,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class VideoFromFile : OpenXmlCompositeElement
+    public partial class VideoFromFile : OpenXmlCompositeElement, IExtensionChildrenParent<VideoFromFile>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "videoFile");
@@ -429,6 +435,9 @@ public StringValue? Link
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -473,7 +482,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QuickTimeFromFile : OpenXmlCompositeElement
+    public partial class QuickTimeFromFile : OpenXmlCompositeElement, IExtensionChildrenParent<QuickTimeFromFile>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "quickTimeFile");
@@ -525,6 +534,9 @@ public StringValue? Link
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2754,7 +2766,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape3DType : OpenXmlCompositeElement
+    public partial class Shape3DType : OpenXmlCompositeElement, IExtensionChildrenParent<Shape3DType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "sp3d");
@@ -2833,6 +2845,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PresetMaterialTypeValues>? Prese
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8673,7 +8688,7 @@ public DocumentFormat.OpenXml.Drawing.EffectDag? EffectDag
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ComplexScriptFont" /> <c>&lt;a:cs></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Fonts : FontCollectionType
+    public partial class Fonts : FontCollectionType, IExtensionChildrenParent<Fonts>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "font");
@@ -8712,6 +8727,9 @@ public Fonts(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8745,7 +8763,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ComplexScriptFont" /> <c>&lt;a:cs></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MajorFont : FontCollectionType
+    public partial class MajorFont : FontCollectionType, IExtensionChildrenParent<MajorFont>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "majorFont");
@@ -8784,6 +8802,9 @@ public MajorFont(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8817,7 +8838,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ComplexScriptFont" /> <c>&lt;a:cs></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class MinorFont : FontCollectionType
+    public partial class MinorFont : FontCollectionType, IExtensionChildrenParent<MinorFont>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "minorFont");
@@ -8856,6 +8877,9 @@ public MinorFont(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8889,7 +8913,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ComplexScriptFont" /> <c>&lt;a:cs></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class FontCollectionType : OpenXmlCompositeElement
+    public abstract partial class FontCollectionType : OpenXmlCompositeElement, IExtensionChildrenParent<FontCollectionType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -8928,6 +8952,9 @@ protected FontCollectionType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10733,7 +10760,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Underline : LinePropertiesType
+    public partial class Underline : LinePropertiesType, IExtensionChildrenParent<Underline>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "uLn");
@@ -10772,6 +10799,9 @@ public Underline(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10837,7 +10867,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Outline : LinePropertiesType
+    public partial class Outline : LinePropertiesType, IExtensionChildrenParent<Outline>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "ln");
@@ -10876,6 +10906,9 @@ public Outline(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10941,7 +10974,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LeftBorderLineProperties : LinePropertiesType
+    public partial class LeftBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<LeftBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnL");
@@ -10980,6 +11013,9 @@ public LeftBorderLineProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11045,7 +11081,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RightBorderLineProperties : LinePropertiesType
+    public partial class RightBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<RightBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnR");
@@ -11084,6 +11120,9 @@ public RightBorderLineProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11149,7 +11188,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TopBorderLineProperties : LinePropertiesType
+    public partial class TopBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<TopBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnT");
@@ -11188,6 +11227,9 @@ public TopBorderLineProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11253,7 +11295,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BottomBorderLineProperties : LinePropertiesType
+    public partial class BottomBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<BottomBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnB");
@@ -11292,6 +11334,9 @@ public BottomBorderLineProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11357,7 +11402,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TopLeftToBottomRightBorderLineProperties : LinePropertiesType
+    public partial class TopLeftToBottomRightBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<TopLeftToBottomRightBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnTlToBr");
@@ -11396,6 +11441,9 @@ public TopLeftToBottomRightBorderLineProperties(string outerXml) : base(outerXml
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11461,7 +11509,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BottomLeftToTopRightBorderLineProperties : LinePropertiesType
+    public partial class BottomLeftToTopRightBorderLineProperties : LinePropertiesType, IExtensionChildrenParent<BottomLeftToTopRightBorderLineProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnBlToTr");
@@ -11500,6 +11548,9 @@ public BottomLeftToTopRightBorderLineProperties(string outerXml) : base(outerXml
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11565,7 +11616,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class LinePropertiesType : OpenXmlCompositeElement
+    public abstract partial class LinePropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<LinePropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -11644,6 +11695,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PenAlignmentValues>? Alignment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12285,7 +12339,7 @@ public DocumentFormat.OpenXml.Drawing.GraphicData? GraphicData
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TintEffect" /> <c>&lt;a:tint></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Blip : OpenXmlCompositeElement
+    public partial class Blip : OpenXmlCompositeElement, IExtensionChildrenParent<Blip>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "blip");
@@ -12360,6 +12414,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlipCompressionValues>? Compress
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12436,7 +12493,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.OfficeStyleSheetExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Theme : OpenXmlPartRootElement
+    public partial class Theme : OpenXmlPartRootElement, IExtensionChildrenParent<Theme>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "theme");
@@ -12498,6 +12555,9 @@ public StringValue? ThemeId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13492,7 +13552,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Scene3DType : OpenXmlCompositeElement
+    public partial class Scene3DType : OpenXmlCompositeElement, IExtensionChildrenParent<Scene3DType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "scene3d");
@@ -13531,6 +13591,9 @@ public Scene3DType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14009,7 +14072,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorScheme : OpenXmlCompositeElement
+    public partial class ColorScheme : OpenXmlCompositeElement, IExtensionChildrenParent<ColorScheme>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "clrScheme");
@@ -14058,6 +14121,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14284,7 +14350,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FontScheme : OpenXmlCompositeElement
+    public partial class FontScheme : OpenXmlCompositeElement, IExtensionChildrenParent<FontScheme>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "fontScheme");
@@ -14333,6 +14399,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -15888,7 +15957,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeLocks : OpenXmlCompositeElement
+    public partial class ShapeLocks : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "spLocks");
@@ -16037,6 +16106,9 @@ public BooleanValue? NoTextEdit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16088,7 +16160,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ConnectorLockingExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConnectionShapeLocks : OpenXmlCompositeElement
+    public partial class ConnectionShapeLocks : OpenXmlCompositeElement, IExtensionChildrenParent<ConnectionShapeLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cxnSpLocks");
@@ -16227,6 +16299,9 @@ public BooleanValue? NoChangeShapeType
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16392,7 +16467,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicFrameLocks : OpenXmlCompositeElement
+    public partial class GraphicFrameLocks : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicFrameLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "graphicFrameLocks");
@@ -16491,6 +16566,9 @@ public BooleanValue? NoResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16885,7 +16963,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Vml.Spreadsheet.ClientData" /> <c>&lt;xvml:ClientData></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicData : OpenXmlCompositeElement
+    public partial class GraphicData : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "graphicData");
@@ -16934,6 +17012,9 @@ public StringValue? Uri
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17818,7 +17899,7 @@ public DocumentFormat.OpenXml.Drawing.Extents? Extents
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvPr");
@@ -17907,6 +17988,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17989,7 +18073,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvSpPr");
@@ -18038,6 +18122,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18202,7 +18289,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualShapeDrawingProperties? NonVisual
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "spPr");
@@ -18251,6 +18338,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18344,7 +18434,7 @@ public DocumentFormat.OpenXml.Drawing.Transform2D? Transform2D
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextShape : OpenXmlCompositeElement
+    public partial class TextShape : OpenXmlCompositeElement, IExtensionChildrenParent<TextShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "txSp");
@@ -18383,6 +18473,9 @@ public TextShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18560,7 +18653,7 @@ public DocumentFormat.OpenXml.Drawing.FontReference? FontReference
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualConnectorShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvCxnSpPr");
@@ -18599,6 +18692,9 @@ public NonVisualConnectorShapeDrawingProperties(string outerXml) : base(outerXml
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18778,7 +18874,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualConnectorShapeDrawingProperties?
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.PictureLocks" /> <c>&lt;a:picLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualPictureDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvPicPr");
@@ -18827,6 +18923,9 @@ public BooleanValue? PreferRelativeResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18978,7 +19077,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualPictureDrawingProperties? NonVisu
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvGraphicFramePr");
@@ -19017,6 +19116,9 @@ public NonVisualGraphicFrameDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19166,7 +19268,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualGraphicFrameDrawingProperties? No
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cNvGrpSpPr");
@@ -19205,6 +19307,9 @@ public NonVisualGroupShapeDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19569,7 +19674,7 @@ public DocumentFormat.OpenXml.Drawing.Rotation? Rotation
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UpVector" /> <c>&lt;a:up></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Backdrop : OpenXmlCompositeElement
+    public partial class Backdrop : OpenXmlCompositeElement, IExtensionChildrenParent<Backdrop>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "backdrop");
@@ -19608,6 +19713,9 @@ public Backdrop(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22424,7 +22532,7 @@ public DocumentFormat.OpenXml.Drawing.ChildExtents? ChildExtents
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeAutoFit" /> <c>&lt;a:spAutoFit></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BodyProperties : OpenXmlCompositeElement
+    public partial class BodyProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BodyProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "bodyPr");
@@ -22653,6 +22761,9 @@ public BooleanValue? CompatibleLineSpacing
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22769,7 +22880,7 @@ public DocumentFormat.OpenXml.Drawing.PresetTextWarp? PresetTextWarp
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ListStyle : OpenXmlCompositeElement
+    public partial class ListStyle : OpenXmlCompositeElement, IExtensionChildrenParent<ListStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lstStyle");
@@ -22808,6 +22919,9 @@ public ListStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23001,7 +23115,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ListStyle" /> <c>&lt;a:lstStyle></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeDefault : DefaultShapeDefinitionType
+    public partial class ShapeDefault : DefaultShapeDefinitionType, IExtensionChildrenParent<ShapeDefault>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "spDef");
@@ -23040,6 +23154,9 @@ public ShapeDefault(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23073,7 +23190,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ListStyle" /> <c>&lt;a:lstStyle></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class LineDefault : DefaultShapeDefinitionType
+    public partial class LineDefault : DefaultShapeDefinitionType, IExtensionChildrenParent<LineDefault>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lnDef");
@@ -23112,6 +23229,9 @@ public LineDefault(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23145,7 +23265,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ListStyle" /> <c>&lt;a:lstStyle></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextDefault : DefaultShapeDefinitionType
+    public partial class TextDefault : DefaultShapeDefinitionType, IExtensionChildrenParent<TextDefault>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "txDef");
@@ -23184,6 +23304,9 @@ public TextDefault(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23217,7 +23340,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ListStyle" /> <c>&lt;a:lstStyle></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class DefaultShapeDefinitionType : OpenXmlCompositeElement
+    public abstract partial class DefaultShapeDefinitionType : OpenXmlCompositeElement, IExtensionChildrenParent<DefaultShapeDefinitionType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -23256,6 +23379,9 @@ protected DefaultShapeDefinitionType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23343,7 +23469,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OverrideColorMapping : ColorMappingType
+    public partial class OverrideColorMapping : ColorMappingType, IExtensionChildrenParent<OverrideColorMapping>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "overrideClrMapping");
@@ -23382,6 +23508,9 @@ public OverrideColorMapping(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23407,7 +23536,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorMap : ColorMappingType
+    public partial class ColorMap : ColorMappingType, IExtensionChildrenParent<ColorMap>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "clrMap");
@@ -23446,6 +23575,9 @@ public ColorMap(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23471,7 +23603,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class ColorMappingType : OpenXmlCompositeElement
+    public abstract partial class ColorMappingType : OpenXmlCompositeElement, IExtensionChildrenParent<ColorMappingType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -23630,6 +23762,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.ColorSchemeIndexValues>? Followe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23819,7 +23954,7 @@ public DocumentFormat.OpenXml.Drawing.ColorMap? ColorMap
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.FormatScheme" /> <c>&lt;a:fmtScheme></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ThemeElements : OpenXmlCompositeElement
+    public partial class ThemeElements : OpenXmlCompositeElement, IExtensionChildrenParent<ThemeElements>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "themeElements");
@@ -23858,6 +23993,9 @@ public ThemeElements(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23944,7 +24082,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Cell3DProperties : OpenXmlCompositeElement
+    public partial class Cell3DProperties : OpenXmlCompositeElement, IExtensionChildrenParent<Cell3DProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cell3D");
@@ -23993,6 +24131,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.PresetMaterialTypeValues>? Prese
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24080,7 +24221,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableCellProperties : OpenXmlCompositeElement
+    public partial class TableCellProperties : OpenXmlCompositeElement, IExtensionChildrenParent<TableCellProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tcPr");
@@ -24199,6 +24340,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.TextHorizontalOverflowValues>? H
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24368,7 +24512,7 @@ public DocumentFormat.OpenXml.Drawing.Cell3DProperties? Cell3DProperties
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TextBody" /> <c>&lt;a:txBody></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableCell : OpenXmlCompositeElement
+    public partial class TableCell : OpenXmlCompositeElement, IExtensionChildrenParent<TableCell>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tc");
@@ -24447,6 +24591,9 @@ public BooleanValue? VerticalMerge
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24537,7 +24684,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NorthwestCell" /> <c>&lt;a:nwCell></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableStyle : TableStyleType
+    public partial class TableStyle : TableStyleType, IExtensionChildrenParent<TableStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tableStyle");
@@ -24576,6 +24723,9 @@ public TableStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24630,7 +24780,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NorthwestCell" /> <c>&lt;a:nwCell></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableStyleEntry : TableStyleType
+    public partial class TableStyleEntry : TableStyleType, IExtensionChildrenParent<TableStyleEntry>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tblStyle");
@@ -24669,6 +24819,9 @@ public TableStyleEntry(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24723,7 +24876,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NorthwestCell" /> <c>&lt;a:nwCell></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class TableStyleType : OpenXmlCompositeElement
+    public abstract partial class TableStyleType : OpenXmlCompositeElement, IExtensionChildrenParent<TableStyleType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -24782,6 +24935,9 @@ public StringValue? StyleName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -25063,7 +25219,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GridColumn : OpenXmlCompositeElement
+    public partial class GridColumn : OpenXmlCompositeElement, IExtensionChildrenParent<GridColumn>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "gridCol");
@@ -25112,6 +25268,9 @@ public Int64Value? Width
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -25167,7 +25326,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TableStyleId" /> <c>&lt;a:tableStyleId></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableProperties : OpenXmlCompositeElement
+    public partial class TableProperties : OpenXmlCompositeElement, IExtensionChildrenParent<TableProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tblPr");
@@ -25276,6 +25435,9 @@ public BooleanValue? BandColumn
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -25411,7 +25573,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TableCell" /> <c>&lt;a:tc></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableRow : OpenXmlCompositeElement
+    public partial class TableRow : OpenXmlCompositeElement, IExtensionChildrenParent<TableRow>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tr");
@@ -25460,6 +25622,9 @@ public Int64Value? Height
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -26115,7 +26280,7 @@ public DocumentFormat.OpenXml.Drawing.LineReference? LineReference
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TopRightToBottomLeftBorder" /> <c>&lt;a:tr2bl></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableCellBorders : OpenXmlCompositeElement
+    public partial class TableCellBorders : OpenXmlCompositeElement, IExtensionChildrenParent<TableCellBorders>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tcBdr");
@@ -26154,6 +26319,9 @@ public TableCellBorders(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -26321,7 +26489,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SystemColor" /> <c>&lt;a:sysClr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableCellTextStyle : OpenXmlCompositeElement
+    public partial class TableCellTextStyle : OpenXmlCompositeElement, IExtensionChildrenParent<TableCellTextStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "tcTxStyle");
@@ -26380,6 +26548,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BooleanStyleValues>? Italic
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27581,7 +27752,7 @@ public DocumentFormat.OpenXml.Drawing.TableCellStyle? TableCellStyle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ParagraphProperties : TextParagraphPropertiesType
+    public partial class ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "pPr");
@@ -27620,6 +27791,9 @@ public ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27701,7 +27875,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DefaultParagraphProperties : TextParagraphPropertiesType
+    public partial class DefaultParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<DefaultParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "defPPr");
@@ -27740,6 +27914,9 @@ public DefaultParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27821,7 +27998,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level1ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level1ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level1ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl1pPr");
@@ -27860,6 +28037,9 @@ public Level1ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27941,7 +28121,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level2ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level2ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level2ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl2pPr");
@@ -27980,6 +28160,9 @@ public Level2ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28061,7 +28244,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level3ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level3ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level3ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl3pPr");
@@ -28100,6 +28283,9 @@ public Level3ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28181,7 +28367,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level4ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level4ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level4ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl4pPr");
@@ -28220,6 +28406,9 @@ public Level4ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28301,7 +28490,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level5ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level5ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level5ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl5pPr");
@@ -28340,6 +28529,9 @@ public Level5ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28421,7 +28613,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level6ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level6ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level6ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl6pPr");
@@ -28460,6 +28652,9 @@ public Level6ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28541,7 +28736,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level7ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level7ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level7ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl7pPr");
@@ -28580,6 +28775,9 @@ public Level7ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28661,7 +28859,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level8ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level8ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level8ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl8pPr");
@@ -28700,6 +28898,9 @@ public Level8ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28781,7 +28982,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Level9ParagraphProperties : TextParagraphPropertiesType
+    public partial class Level9ParagraphProperties : TextParagraphPropertiesType, IExtensionChildrenParent<Level9ParagraphProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "lvl9pPr");
@@ -28820,6 +29021,9 @@ public Level9ParagraphProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28901,7 +29105,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.TabStopList" /> <c>&lt;a:tabLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class TextParagraphPropertiesType : OpenXmlCompositeElement
+    public abstract partial class TextParagraphPropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<TextParagraphPropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -29050,6 +29254,9 @@ public BooleanValue? Height
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -29174,7 +29381,7 @@ public DocumentFormat.OpenXml.Drawing.SpaceAfter? SpaceAfter
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UnderlineFollowsText" /> <c>&lt;a:uLnTx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class EndParagraphRunProperties : TextCharacterPropertiesType
+    public partial class EndParagraphRunProperties : TextCharacterPropertiesType, IExtensionChildrenParent<EndParagraphRunProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "endParaRPr");
@@ -29213,6 +29420,9 @@ public EndParagraphRunProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -29304,7 +29514,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UnderlineFollowsText" /> <c>&lt;a:uLnTx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RunProperties : TextCharacterPropertiesType
+    public partial class RunProperties : TextCharacterPropertiesType, IExtensionChildrenParent<RunProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "rPr");
@@ -29343,6 +29553,9 @@ public RunProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -29434,7 +29647,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UnderlineFollowsText" /> <c>&lt;a:uLnTx></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DefaultRunProperties : TextCharacterPropertiesType
+    public partial class DefaultRunProperties : TextCharacterPropertiesType, IExtensionChildrenParent<DefaultRunProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "defRPr");
@@ -29473,6 +29686,9 @@ public DefaultRunProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -29564,7 +29780,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.UnderlineFollowsText" /> <c>&lt;a:uLnTx></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class TextCharacterPropertiesType : OpenXmlCompositeElement
+    public abstract partial class TextCharacterPropertiesType : OpenXmlCompositeElement, IExtensionChildrenParent<TextCharacterPropertiesType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -29793,6 +30009,9 @@ public StringValue? Bookmark
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -30869,7 +31088,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualGroupShapeDrawingProperties? NonV
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class VisualGroupShapeProperties : OpenXmlCompositeElement
+    public partial class VisualGroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<VisualGroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "grpSpPr");
@@ -30918,6 +31137,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -30998,7 +31220,7 @@ public DocumentFormat.OpenXml.Drawing.TransformGroup? TransformGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeStyle" /> <c>&lt;a:style></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape : OpenXmlCompositeElement
+    public partial class Shape : OpenXmlCompositeElement, IExtensionChildrenParent<Shape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "sp");
@@ -31037,6 +31259,9 @@ public Shape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -31139,7 +31364,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeStyle" /> <c>&lt;a:style></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConnectionShape : OpenXmlCompositeElement
+    public partial class ConnectionShape : OpenXmlCompositeElement, IExtensionChildrenParent<ConnectionShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "cxnSp");
@@ -31178,6 +31403,9 @@ public ConnectionShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -31266,7 +31494,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeStyle" /> <c>&lt;a:style></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Picture : OpenXmlCompositeElement
+    public partial class Picture : OpenXmlCompositeElement, IExtensionChildrenParent<Picture>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "pic");
@@ -31305,6 +31533,9 @@ public Picture(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -31407,7 +31638,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicFrame : OpenXmlCompositeElement
+    public partial class GraphicFrame : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicFrame>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "graphicFrame");
@@ -31446,6 +31677,9 @@ public GraphicFrame(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -31539,7 +31773,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Drawing.GvmlContentPart" /> <c>&lt;a14:contentPart></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShape : OpenXmlCompositeElement
+    public partial class GroupShape : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "grpSp");
@@ -31578,6 +31812,9 @@ public GroupShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -31962,7 +32199,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeLocks : OpenXmlCompositeElement
+    public partial class GroupShapeLocks : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "grpSpLocks");
@@ -32071,6 +32308,9 @@ public BooleanValue? NoResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32186,7 +32426,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ObjectDefaults : OpenXmlCompositeElement
+    public partial class ObjectDefaults : OpenXmlCompositeElement, IExtensionChildrenParent<ObjectDefaults>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "objectDefaults");
@@ -32225,6 +32465,9 @@ public ObjectDefaults(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32505,7 +32748,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.HyperlinkExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HyperlinkOnClick : HyperlinkType
+    public partial class HyperlinkOnClick : HyperlinkType, IExtensionChildrenParent<HyperlinkOnClick>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "hlinkClick");
@@ -32544,6 +32787,9 @@ public HyperlinkOnClick(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32573,7 +32819,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.HyperlinkExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HyperlinkOnMouseOver : HyperlinkType
+    public partial class HyperlinkOnMouseOver : HyperlinkType, IExtensionChildrenParent<HyperlinkOnMouseOver>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "hlinkMouseOver");
@@ -32612,6 +32858,9 @@ public HyperlinkOnMouseOver(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32641,7 +32890,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.HyperlinkExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HyperlinkOnHover : HyperlinkType
+    public partial class HyperlinkOnHover : HyperlinkType, IExtensionChildrenParent<HyperlinkOnHover>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "hlinkHover");
@@ -32680,6 +32929,9 @@ public HyperlinkOnHover(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32708,7 +32960,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.HyperlinkExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class HyperlinkType : OpenXmlCompositeElement
+    public abstract partial class HyperlinkType : OpenXmlCompositeElement, IExtensionChildrenParent<HyperlinkType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -32830,6 +33082,9 @@ public BooleanValue? EndSound
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -33746,7 +34001,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PictureLocks : OpenXmlCompositeElement
+    public partial class PictureLocks : OpenXmlCompositeElement, IExtensionChildrenParent<PictureLocks>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/main", "picLocks");
@@ -33895,6 +34150,9 @@ public BooleanValue? NoCrop
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_picture.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_picture.g.cs
index f3d2abe0f..c9954477a 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_picture.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_picture.g.cs
@@ -33,7 +33,7 @@ namespace DocumentFormat.OpenXml.Drawing.Pictures
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Pictures.NonVisualPictureProperties" /> <c>&lt;pic:nvPicPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Picture : OpenXmlCompositeElement
+    public partial class Picture : OpenXmlCompositeElement, IExtensionChildrenParent<Picture>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/picture", "pic");
@@ -72,6 +72,9 @@ public Picture(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -173,7 +176,7 @@ public DocumentFormat.OpenXml.Office2010.Drawing.Pictures.OfficeArtExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/picture", "cNvPr");
@@ -262,6 +265,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -345,7 +351,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.PictureLocks" /> <c>&lt;a:picLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualPictureDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/picture", "cNvPicPr");
@@ -394,6 +400,9 @@ public BooleanValue? PreferRelativeResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -687,7 +696,7 @@ public DocumentFormat.OpenXml.Drawing.SourceRectangle? SourceRectangle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/picture", "spPr");
@@ -736,6 +745,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_spreadsheetDrawing.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_spreadsheetDrawing.g.cs
index 11c1d5fa9..ce5cec0e6 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_spreadsheetDrawing.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_spreadsheetDrawing.g.cs
@@ -1124,7 +1124,7 @@ public DocumentFormat.OpenXml.Drawing.Spreadsheet.ShapeStyle? ShapeStyle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.Drawing.ExcelNonVisualContentPartShapeProperties" /> <c>&lt;xdr14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPart : OpenXmlCompositeElement
+    public partial class ContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "contentPart");
@@ -1186,6 +1186,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1496,7 +1499,7 @@ public DocumentFormat.OpenXml.Drawing.Spreadsheet.NonVisualShapeDrawingPropertie
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "spPr");
@@ -1545,6 +1548,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2994,7 +3000,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvPr");
@@ -3083,6 +3089,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3166,7 +3175,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvSpPr");
@@ -3215,6 +3224,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3274,7 +3286,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualConnectorShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvCxnSpPr");
@@ -3313,6 +3325,9 @@ public NonVisualConnectorShapeDrawingProperties(string outerXml) : base(outerXml
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3398,7 +3413,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.PictureLocks" /> <c>&lt;a:picLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualPictureDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvPicPr");
@@ -3447,6 +3462,9 @@ public BooleanValue? PreferRelativeResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3504,7 +3522,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualPicturePropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvGraphicFramePr");
@@ -3543,6 +3561,9 @@ public NonVisualGraphicFrameDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3598,7 +3619,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "cNvGrpSpPr");
@@ -3637,6 +3658,9 @@ public NonVisualGroupShapeDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3795,7 +3819,7 @@ public DocumentFormat.OpenXml.Drawing.Spreadsheet.NonVisualGroupShapeDrawingProp
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing", "grpSpPr");
@@ -3844,6 +3868,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_wordprocessingDrawing.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_wordprocessingDrawing.g.cs
index 1881b6a6a..60c988923 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_wordprocessingDrawing.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_drawingml_2006_wordprocessingDrawing.g.cs
@@ -1760,7 +1760,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DocProperties : OpenXmlCompositeElement
+    public partial class DocProperties : OpenXmlCompositeElement, IExtensionChildrenParent<DocProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing", "docPr");
@@ -1849,6 +1849,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1932,7 +1935,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing", "cNvGraphicFramePr");
@@ -1971,6 +1974,9 @@ public NonVisualGraphicFrameDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_presentationml_2006_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_presentationml_2006_main.g.cs
index 15efa8d47..2ab3a2fb9 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_presentationml_2006_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_presentationml_2006_main.g.cs
@@ -802,7 +802,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ColorMap : OpenXmlCompositeElement
+    public partial class ColorMap : OpenXmlCompositeElement, IExtensionChildrenParent<ColorMap>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "clrMap");
@@ -961,6 +961,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.ColorSchemeIndexValues>? Followe
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1165,7 +1168,7 @@ public DocumentFormat.OpenXml.Drawing.OverrideColorMapping? OverrideColorMapping
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BackgroundProperties : OpenXmlCompositeElement
+    public partial class BackgroundProperties : OpenXmlCompositeElement, IExtensionChildrenParent<BackgroundProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "bgPr");
@@ -1214,6 +1217,9 @@ public BooleanValue? ShadeToTitle
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1912,7 +1918,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.SlideSize" /> <c>&lt;p:sldSz></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Presentation : OpenXmlPartRootElement
+    public partial class Presentation : OpenXmlPartRootElement, IExtensionChildrenParent<Presentation>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "presentation");
@@ -2071,6 +2077,9 @@ public EnumValue<DocumentFormat.OpenXml.Presentation.ConformanceClassValues>? Co
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2358,7 +2367,7 @@ public PresentationPart? PresentationPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.WebProperties" /> <c>&lt;p:webPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PresentationProperties : OpenXmlPartRootElement
+    public partial class PresentationProperties : OpenXmlPartRootElement, IExtensionChildrenParent<PresentationProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "presentationPr");
@@ -2397,6 +2406,9 @@ public PresentationProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2546,7 +2558,7 @@ public PresentationPropertiesPart? PresentationPropertiesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Transition" /> <c>&lt;p:transition></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Slide : OpenXmlPartRootElement
+    public partial class Slide : OpenXmlPartRootElement, IExtensionChildrenParent<Slide>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sld");
@@ -2615,6 +2627,9 @@ public BooleanValue? Show
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2761,7 +2776,7 @@ public SlidePart? SlidePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Transition" /> <c>&lt;p:transition></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideLayout : OpenXmlPartRootElement
+    public partial class SlideLayout : OpenXmlPartRootElement, IExtensionChildrenParent<SlideLayout>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldLayout");
@@ -2860,6 +2875,9 @@ public BooleanValue? UserDrawn
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3028,7 +3046,7 @@ public SlideLayoutPart? SlideLayoutPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Transition" /> <c>&lt;p:transition></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideMaster : OpenXmlPartRootElement
+    public partial class SlideMaster : OpenXmlPartRootElement, IExtensionChildrenParent<SlideMaster>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldMaster");
@@ -3077,6 +3095,9 @@ public BooleanValue? Preserve
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3263,7 +3284,7 @@ public SlideMasterPart? SlideMasterPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.HeaderFooter" /> <c>&lt;p:hf></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HandoutMaster : OpenXmlPartRootElement
+    public partial class HandoutMaster : OpenXmlPartRootElement, IExtensionChildrenParent<HandoutMaster>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "handoutMaster");
@@ -3302,6 +3323,9 @@ public HandoutMaster(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3427,7 +3451,7 @@ public HandoutMasterPart? HandoutMasterPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.NotesMasterExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesMaster : OpenXmlPartRootElement
+    public partial class NotesMaster : OpenXmlPartRootElement, IExtensionChildrenParent<NotesMaster>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notesMaster");
@@ -3466,6 +3490,9 @@ public NotesMaster(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3604,7 +3631,7 @@ public NotesMasterPart? NotesMasterPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionListWithModification" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesSlide : OpenXmlPartRootElement
+    public partial class NotesSlide : OpenXmlPartRootElement, IExtensionChildrenParent<NotesSlide>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notes");
@@ -3663,6 +3690,9 @@ public BooleanValue? ShowMasterPlaceholderAnimations
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3772,7 +3802,7 @@ public NotesSlidePart? NotesSlidePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideSyncProperties : OpenXmlPartRootElement
+    public partial class SlideSyncProperties : OpenXmlPartRootElement, IExtensionChildrenParent<SlideSyncProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldSyncPr");
@@ -3841,6 +3871,9 @@ public DateTimeValue? ClientInsertedTime
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4027,7 +4060,7 @@ public UserDefinedTagsPart? UserDefinedTagsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.SlideViewProperties" /> <c>&lt;p:slideViewPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ViewProperties : OpenXmlPartRootElement
+    public partial class ViewProperties : OpenXmlPartRootElement, IExtensionChildrenParent<ViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "viewPr");
@@ -4086,6 +4119,9 @@ public BooleanValue? ShowComments
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4269,7 +4305,7 @@ public ViewPropertiesPart? ViewPropertiesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.PowerPoint.NonVisualContentPartProperties" /> <c>&lt;p14:nvContentPartPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ContentPart : OpenXmlCompositeElement
+    public partial class ContentPart : OpenXmlCompositeElement, IExtensionChildrenParent<ContentPart>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "contentPart");
@@ -4334,6 +4370,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10812,7 +10851,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.CommentAuthorExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommentAuthor : OpenXmlCompositeElement
+    public partial class CommentAuthor : OpenXmlCompositeElement, IExtensionChildrenParent<CommentAuthor>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cmAuthor");
@@ -10901,6 +10940,9 @@ public UInt32Value? ColorIndex
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10966,7 +11008,7 @@ public DocumentFormat.OpenXml.Presentation.CommentAuthorExtensionList? CommentAu
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Text" /> <c>&lt;p:text></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Comment : OpenXmlCompositeElement
+    public partial class Comment : OpenXmlCompositeElement, IExtensionChildrenParent<Comment>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cm");
@@ -11035,6 +11077,9 @@ public UInt32Value? Index
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11186,7 +11231,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Picture" /> <c>&lt;p:pic></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Control : OpenXmlCompositeElement
+    public partial class Control : OpenXmlCompositeElement, IExtensionChildrenParent<Control>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "control");
@@ -11288,6 +11333,9 @@ public Int32Value? ImageHeight
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11358,7 +11406,7 @@ public DocumentFormat.OpenXml.Presentation.Picture? Picture
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideId : OpenXmlCompositeElement
+    public partial class SlideId : OpenXmlCompositeElement, IExtensionChildrenParent<SlideId>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldId");
@@ -11420,11 +11468,15 @@ public StringValue? RelationshipId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+            DocumentFormat.OpenXml.Presentation.Picture.ElementType,
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
             builder.SetSchema(ElementType);
-            builder.AddChild(DocumentFormat.OpenXml.Presentation.ExtensionList.ElementType, static () => new DocumentFormat.OpenXml.Presentation.ExtensionList());
+            builder.AddChild(DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>.ElementType, static () => new DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>());
             builder.AddElement<SlideId>()
                 .AddAttribute("id", a => a.Id, aBuilder =>
                 {
@@ -11437,7 +11489,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
                 });
             builder.Particle = new CompositeParticle.Builder(ParticleType.Sequence, 1, 1)
             {
-                new ElementParticle(DocumentFormat.OpenXml.Presentation.ExtensionList.ElementType, 0, 1)
+                new ElementParticle(DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>.ElementType, 0, 1),
             };
             builder.AddConstraint(new UniqueAttributeValueConstraint(builder.CreateQName(":id"), true, null));
             builder.AddConstraint(new RelationshipExistConstraint(builder.CreateQName("r:id")));
@@ -11450,10 +11502,10 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         /// <remarks>
         /// xmlns:p = http://schemas.openxmlformats.org/presentationml/2006/main
         /// </remarks>
-        public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
+        public DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>? ExtensionList
         {
-            get => GetElement(DocumentFormat.OpenXml.Presentation.ExtensionList.ElementType) as DocumentFormat.OpenXml.Presentation.ExtensionList;
-            set => SetElement(value, DocumentFormat.OpenXml.Presentation.ExtensionList.ElementType);
+            get => GetElement(DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>.ElementType) as DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>;
+            set => SetElement(value, DocumentFormat.OpenXml.Presentation.ExtensionList<DocumentFormat.OpenXml.Presentation.SlideId>.ElementType);
         }
 
         /// <inheritdoc/>
@@ -11471,7 +11523,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideMasterId : OpenXmlCompositeElement
+    public partial class SlideMasterId : OpenXmlCompositeElement, IExtensionChildrenParent<SlideMasterId>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldMasterId");
@@ -11533,6 +11585,9 @@ public StringValue? RelationshipId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11583,7 +11638,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesMasterId : OpenXmlCompositeElement
+    public partial class NotesMasterId : OpenXmlCompositeElement, IExtensionChildrenParent<NotesMasterId>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notesMasterId");
@@ -11635,6 +11690,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -11680,7 +11738,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HandoutMasterId : OpenXmlCompositeElement
+    public partial class HandoutMasterId : OpenXmlCompositeElement, IExtensionChildrenParent<HandoutMasterId>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "handoutMasterId");
@@ -11732,6 +11790,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12227,7 +12288,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.SlideList" /> <c>&lt;p:sldLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CustomShow : OpenXmlCompositeElement
+    public partial class CustomShow : OpenXmlCompositeElement, IExtensionChildrenParent<CustomShow>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "custShow");
@@ -12286,6 +12347,9 @@ public UInt32Value? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12352,7 +12416,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvPr");
@@ -12441,6 +12505,9 @@ public StringValue? Title
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12523,7 +12590,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualDrawingPropertiesExtensionList? N
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ShapeLocks" /> <c>&lt;a:spLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvSpPr");
@@ -12572,6 +12639,9 @@ public BooleanValue? TextBox
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12635,7 +12705,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.PlaceholderShape" /> <c>&lt;p:ph></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ApplicationNonVisualDrawingProperties : OpenXmlCompositeElement
+    public partial class ApplicationNonVisualDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ApplicationNonVisualDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "nvPr");
@@ -12694,6 +12764,9 @@ public BooleanValue? UserDrawn
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12880,7 +12953,7 @@ public DocumentFormat.OpenXml.Presentation.ApplicationNonVisualDrawingProperties
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Transform2D" /> <c>&lt;a:xfrm></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeProperties : OpenXmlCompositeElement
+    public partial class ShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "spPr");
@@ -12929,6 +13002,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13245,7 +13321,7 @@ public DocumentFormat.OpenXml.Drawing.ListStyle? ListStyle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualConnectorShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualConnectorShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvCxnSpPr");
@@ -13284,6 +13360,9 @@ public NonVisualConnectorShapeDrawingProperties(string outerXml) : base(outerXml
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13479,7 +13558,7 @@ public DocumentFormat.OpenXml.Presentation.ApplicationNonVisualDrawingProperties
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.PictureLocks" /> <c>&lt;a:picLocks></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualPictureDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualPictureDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvPicPr");
@@ -13528,6 +13607,9 @@ public BooleanValue? PreferRelativeResize
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13824,7 +13906,7 @@ public DocumentFormat.OpenXml.Drawing.SourceRectangle? SourceRectangle
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.ExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGraphicFrameDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGraphicFrameDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvGraphicFramePr");
@@ -13863,6 +13945,9 @@ public NonVisualGraphicFrameDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14156,7 +14241,7 @@ public DocumentFormat.OpenXml.Drawing.Extents? Extents
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionList" /> <c>&lt;a:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement
+    public partial class NonVisualGroupShapeDrawingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NonVisualGroupShapeDrawingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cNvGrpSpPr");
@@ -14195,6 +14280,9 @@ public NonVisualGroupShapeDrawingProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14259,7 +14347,7 @@ public DocumentFormat.OpenXml.Drawing.NonVisualGroupDrawingShapePropsExtensionLi
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TitleStyle : TextListStyleType
+    public partial class TitleStyle : TextListStyleType, IExtensionChildrenParent<TitleStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "titleStyle");
@@ -14298,6 +14386,9 @@ public TitleStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14343,7 +14434,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class BodyStyle : TextListStyleType
+    public partial class BodyStyle : TextListStyleType, IExtensionChildrenParent<BodyStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "bodyStyle");
@@ -14382,6 +14473,9 @@ public BodyStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14427,7 +14521,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OtherStyle : TextListStyleType
+    public partial class OtherStyle : TextListStyleType, IExtensionChildrenParent<OtherStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "otherStyle");
@@ -14466,6 +14560,9 @@ public OtherStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14511,7 +14608,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DefaultTextStyle : TextListStyleType
+    public partial class DefaultTextStyle : TextListStyleType, IExtensionChildrenParent<DefaultTextStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "defaultTextStyle");
@@ -14550,6 +14647,9 @@ public DefaultTextStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14595,7 +14695,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesStyle : TextListStyleType
+    public partial class NotesStyle : TextListStyleType, IExtensionChildrenParent<NotesStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notesStyle");
@@ -14634,6 +14734,9 @@ public NotesStyle(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14679,7 +14782,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.Level9ParagraphProperties" /> <c>&lt;a:lvl9pPr></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class TextListStyleType : OpenXmlCompositeElement
+    public abstract partial class TextListStyleType : OpenXmlCompositeElement, IExtensionChildrenParent<TextListStyleType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -14718,6 +14821,9 @@ protected TextListStyleType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14889,7 +14995,7 @@ public DocumentFormat.OpenXml.Drawing.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideLayoutId : OpenXmlCompositeElement
+    public partial class SlideLayoutId : OpenXmlCompositeElement, IExtensionChildrenParent<SlideLayoutId>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sldLayoutId");
@@ -14951,6 +15057,9 @@ public StringValue? RelationshipId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -15005,7 +15114,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ShapeTree" /> <c>&lt;p:spTree></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CommonSlideData : OpenXmlCompositeElement
+    public partial class CommonSlideData : OpenXmlCompositeElement, IExtensionChildrenParent<CommonSlideData>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cSld");
@@ -15054,6 +15163,9 @@ public StringValue? Name
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16021,7 +16133,7 @@ public DocumentFormat.OpenXml.Presentation.GuideList? GuideList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.RestoredTop" /> <c>&lt;p:restoredTop></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NormalViewProperties : OpenXmlCompositeElement
+    public partial class NormalViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NormalViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "normalViewPr");
@@ -16110,6 +16222,9 @@ public BooleanValue? PreferSingleView
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16192,7 +16307,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SlideViewProperties : OpenXmlCompositeElement
+    public partial class SlideViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<SlideViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "slideViewPr");
@@ -16231,6 +16346,9 @@ public SlideViewProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16287,7 +16405,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.OutlineViewSlideList" /> <c>&lt;p:sldLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OutlineViewProperties : OpenXmlCompositeElement
+    public partial class OutlineViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<OutlineViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "outlineViewPr");
@@ -16326,6 +16444,9 @@ public OutlineViewProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16396,7 +16517,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesTextViewProperties : OpenXmlCompositeElement
+    public partial class NotesTextViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NotesTextViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notesTextViewPr");
@@ -16435,6 +16556,9 @@ public NotesTextViewProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16490,7 +16614,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SorterViewProperties : OpenXmlCompositeElement
+    public partial class SorterViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<SorterViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sorterViewPr");
@@ -16539,6 +16663,9 @@ public BooleanValue? ShowFormatting
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16596,7 +16723,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NotesViewProperties : OpenXmlCompositeElement
+    public partial class NotesViewProperties : OpenXmlCompositeElement, IExtensionChildrenParent<NotesViewProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "notesViewPr");
@@ -16635,6 +16762,9 @@ public NotesViewProperties(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17068,7 +17198,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.NonVisualPictureProperties" /> <c>&lt;p:nvPicPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Picture : OpenXmlCompositeElement
+    public partial class Picture : OpenXmlCompositeElement, IExtensionChildrenParent<Picture>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "pic");
@@ -17107,6 +17237,9 @@ public Picture(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17206,7 +17339,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionListWithModification? Extens
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OleObjectEmbed : OpenXmlCompositeElement
+    public partial class OleObjectEmbed : OpenXmlCompositeElement, IExtensionChildrenParent<OleObjectEmbed>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "embed");
@@ -17255,6 +17388,9 @@ public EnumValue<DocumentFormat.OpenXml.Presentation.OleObjectFollowColorSchemeV
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17299,7 +17435,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OleObjectLink : OpenXmlCompositeElement
+    public partial class OleObjectLink : OpenXmlCompositeElement, IExtensionChildrenParent<OleObjectLink>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "link");
@@ -17348,6 +17484,9 @@ public BooleanValue? AutoUpdate
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17431,7 +17570,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.PowerPoint.PresetTransition" /> <c>&lt;p15:prstTrans></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Transition : OpenXmlCompositeElement
+    public partial class Transition : OpenXmlCompositeElement, IExtensionChildrenParent<Transition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "transition");
@@ -17513,6 +17652,9 @@ public StringValue? AdvanceAfterTime
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17645,7 +17787,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.TimeNodeList" /> <c>&lt;p:tnLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Timing : OpenXmlCompositeElement
+    public partial class Timing : OpenXmlCompositeElement, IExtensionChildrenParent<Timing>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "timing");
@@ -17684,6 +17826,9 @@ public Timing(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17941,7 +18086,7 @@ public DocumentFormat.OpenXml.Presentation.BackgroundStyleReference? BackgroundS
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Shape" /> <c>&lt;p:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShapeTree : GroupShapeType
+    public partial class ShapeTree : GroupShapeType, IExtensionChildrenParent<ShapeTree>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "spTree");
@@ -17980,6 +18125,9 @@ public ShapeTree(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18024,7 +18172,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Shape" /> <c>&lt;p:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShape : GroupShapeType
+    public partial class GroupShape : GroupShapeType, IExtensionChildrenParent<GroupShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "grpSp");
@@ -18063,6 +18211,9 @@ public GroupShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18107,7 +18258,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.Shape" /> <c>&lt;p:sp></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class GroupShapeType : OpenXmlCompositeElement
+    public abstract partial class GroupShapeType : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -18146,6 +18297,9 @@ protected GroupShapeType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18516,7 +18670,7 @@ public DocumentFormat.OpenXml.Presentation.ApplicationNonVisualDrawingProperties
     ///   <item><description><see cref="DocumentFormat.OpenXml.Drawing.SolidFill" /> <c>&lt;a:solidFill></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupShapeProperties : OpenXmlCompositeElement
+    public partial class GroupShapeProperties : OpenXmlCompositeElement, IExtensionChildrenParent<GroupShapeProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "grpSpPr");
@@ -18565,6 +18719,9 @@ public EnumValue<DocumentFormat.OpenXml.Drawing.BlackWhiteModeValues>? BlackWhit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18645,7 +18802,7 @@ public DocumentFormat.OpenXml.Drawing.TransformGroup? TransformGroup
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.NonVisualShapeProperties" /> <c>&lt;p:nvSpPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Shape : OpenXmlCompositeElement
+    public partial class Shape : OpenXmlCompositeElement, IExtensionChildrenParent<Shape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "sp");
@@ -18694,6 +18851,9 @@ public BooleanValue? UseBackgroundFill
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18798,7 +18958,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionListWithModification? Extens
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.NonVisualGraphicFrameProperties" /> <c>&lt;p:nvGraphicFramePr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GraphicFrame : OpenXmlCompositeElement
+    public partial class GraphicFrame : OpenXmlCompositeElement, IExtensionChildrenParent<GraphicFrame>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "graphicFrame");
@@ -18837,6 +18997,9 @@ public GraphicFrame(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18924,7 +19087,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionListWithModification? Extens
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionListWithModification" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConnectionShape : OpenXmlCompositeElement
+    public partial class ConnectionShape : OpenXmlCompositeElement, IExtensionChildrenParent<ConnectionShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "cxnSp");
@@ -18963,6 +19126,9 @@ public ConnectionShape(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19866,7 +20032,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionListWithModification" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PlaceholderShape : OpenXmlCompositeElement
+    public partial class PlaceholderShape : OpenXmlCompositeElement, IExtensionChildrenParent<PlaceholderShape>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "ph");
@@ -19955,6 +20121,9 @@ public BooleanValue? HasCustomPrompt
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21397,7 +21566,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PhotoAlbum : OpenXmlCompositeElement
+    public partial class PhotoAlbum : OpenXmlCompositeElement, IExtensionChildrenParent<PhotoAlbum>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "photoAlbum");
@@ -21476,6 +21645,9 @@ public EnumValue<DocumentFormat.OpenXml.Presentation.PhotoAlbumFrameShapeValues>
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22006,7 +22178,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.SlideRange" /> <c>&lt;p:sldRg></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HtmlPublishProperties : OpenXmlCompositeElement
+    public partial class HtmlPublishProperties : OpenXmlCompositeElement, IExtensionChildrenParent<HtmlPublishProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "htmlPubPr");
@@ -22078,6 +22250,9 @@ public StringValue? Id
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22126,7 +22301,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WebProperties : OpenXmlCompositeElement
+    public partial class WebProperties : OpenXmlCompositeElement, IExtensionChildrenParent<WebProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "webPr");
@@ -22255,6 +22430,9 @@ public EnumValue<DocumentFormat.OpenXml.Presentation.WebColorValues>? Color
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22310,7 +22488,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PrintingProperties : OpenXmlCompositeElement
+    public partial class PrintingProperties : OpenXmlCompositeElement, IExtensionChildrenParent<PrintingProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "prnPr");
@@ -22399,6 +22577,9 @@ public BooleanValue? FrameSlides
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22457,7 +22638,7 @@ public DocumentFormat.OpenXml.Presentation.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ShowPropertiesExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ShowProperties : OpenXmlCompositeElement
+    public partial class ShowProperties : OpenXmlCompositeElement, IExtensionChildrenParent<ShowProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "showPr");
@@ -22536,6 +22717,9 @@ public BooleanValue? UseTimings
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -22847,7 +23031,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionListWithModification" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class HeaderFooter : OpenXmlCompositeElement
+    public partial class HeaderFooter : OpenXmlCompositeElement, IExtensionChildrenParent<HeaderFooter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "hf");
@@ -22926,6 +23110,9 @@ public BooleanValue? DateTime
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23103,7 +23290,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Presentation.ExtensionList" /> <c>&lt;p:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TextStyles : OpenXmlCompositeElement
+    public partial class TextStyles : OpenXmlCompositeElement, IExtensionChildrenParent<TextStyles>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "txStyles");
@@ -23142,6 +23329,9 @@ public TextStyles(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_spreadsheetml_2006_main.g.cs b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_spreadsheetml_2006_main.g.cs
index 6b431d3d3..e0ee0c215 100644
--- a/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_spreadsheetml_2006_main.g.cs
+++ b/generated/DocumentFormat.OpenXml/DocumentFormat.OpenXml.Generator/DocumentFormat.OpenXml.Generator.OpenXmlGenerator/schemas_openxmlformats_org_spreadsheetml_2006_main.g.cs
@@ -115,7 +115,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CalculationChain : OpenXmlPartRootElement
+    public partial class CalculationChain : OpenXmlPartRootElement, IExtensionChildrenParent<CalculationChain>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "calcChain");
@@ -154,6 +154,9 @@ public CalculationChain(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -215,7 +218,7 @@ public CalculationChainPart? CalculationChainPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Comments : OpenXmlPartRootElement
+    public partial class Comments : OpenXmlPartRootElement, IExtensionChildrenParent<Comments>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "comments");
@@ -254,6 +257,9 @@ public Comments(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -574,7 +580,7 @@ public ConnectionsPart? ConnectionsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.TupleCache" /> <c>&lt;x:tupleCache></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotCacheDefinition : OpenXmlPartRootElement
+    public partial class PivotCacheDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<PivotCacheDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotCacheDefinition");
@@ -806,6 +812,9 @@ public BooleanValue? SupportAdvancedDrill
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1048,7 +1057,7 @@ public PivotTableCacheDefinitionPart? PivotTableCacheDefinitionPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotCacheRecord" /> <c>&lt;x:r></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotCacheRecords : OpenXmlPartRootElement
+    public partial class PivotCacheRecords : OpenXmlPartRootElement, IExtensionChildrenParent<PivotCacheRecords>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotCacheRecords");
@@ -1097,6 +1106,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -1174,7 +1186,7 @@ public PivotTableCacheRecordsPart? PivotTableCacheRecordsPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.RowItems" /> <c>&lt;x:rowItems></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotTableDefinition : OpenXmlPartRootElement
+    public partial class PivotTableDefinition : OpenXmlPartRootElement, IExtensionChildrenParent<PivotTableDefinition>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotTableDefinition");
@@ -1893,6 +1905,9 @@ public BooleanValue? CustomListSort
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2295,7 +2310,7 @@ public PivotTablePart? PivotTablePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.QueryTableRefresh" /> <c>&lt;x:queryTableRefresh></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QueryTable : OpenXmlPartRootElement
+    public partial class QueryTable : OpenXmlPartRootElement, IExtensionChildrenParent<QueryTable>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "queryTable");
@@ -2554,6 +2569,9 @@ public BooleanValue? ApplyWidthHeightFormats
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -2673,7 +2691,7 @@ public QueryTablePart? QueryTablePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SharedStringItem" /> <c>&lt;x:si></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SharedStringTable : OpenXmlPartRootElement
+    public partial class SharedStringTable : OpenXmlPartRootElement, IExtensionChildrenParent<SharedStringTable>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sst");
@@ -2732,6 +2750,9 @@ public UInt32Value? UniqueCount
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3311,7 +3332,7 @@ public WorkbookUserDataPart? WorkbookUserDataPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.WorksheetExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Worksheet : OpenXmlPartRootElement
+    public partial class Worksheet : OpenXmlPartRootElement, IExtensionChildrenParent<Worksheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "worksheet");
@@ -3350,6 +3371,9 @@ public Worksheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3546,7 +3570,7 @@ public WorksheetPart? WorksheetPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.WebPublishItems" /> <c>&lt;x:webPublishItems></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Chartsheet : OpenXmlPartRootElement
+    public partial class Chartsheet : OpenXmlPartRootElement, IExtensionChildrenParent<Chartsheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "chartsheet");
@@ -3585,6 +3609,9 @@ public Chartsheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -3865,7 +3892,7 @@ public ChartsheetPart? ChartsheetPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SheetViews" /> <c>&lt;x:sheetViews></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DialogSheet : OpenXmlPartRootElement
+    public partial class DialogSheet : OpenXmlPartRootElement, IExtensionChildrenParent<DialogSheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "dialogsheet");
@@ -3904,6 +3931,9 @@ public DialogSheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4205,7 +4235,7 @@ public DialogsheetPart? DialogsheetPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.MetadataTypes" /> <c>&lt;x:metadataTypes></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Metadata : OpenXmlPartRootElement
+    public partial class Metadata : OpenXmlPartRootElement, IExtensionChildrenParent<Metadata>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "metadata");
@@ -4244,6 +4274,9 @@ public Metadata(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4458,7 +4491,7 @@ public SingleCellTablePart? SingleCellTablePart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.TableStyles" /> <c>&lt;x:tableStyles></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Stylesheet : OpenXmlPartRootElement
+    public partial class Stylesheet : OpenXmlPartRootElement, IExtensionChildrenParent<Stylesheet>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "styleSheet");
@@ -4497,6 +4530,9 @@ public Stylesheet(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4720,7 +4756,7 @@ public WorkbookStylesPart? WorkbookStylesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.OleLink" /> <c>&lt;x:oleLink></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ExternalLink : OpenXmlPartRootElement
+    public partial class ExternalLink : OpenXmlPartRootElement, IExtensionChildrenParent<ExternalLink>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "externalLink");
@@ -4759,6 +4795,9 @@ public ExternalLink(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -4829,7 +4868,7 @@ public ExternalWorkbookPart? ExternalWorkbookPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.TableStyleInfo" /> <c>&lt;x:tableStyleInfo></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Table : OpenXmlPartRootElement
+    public partial class Table : OpenXmlPartRootElement, IExtensionChildrenParent<Table>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "table");
@@ -5088,6 +5127,9 @@ public UInt32Value? ConnectionId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5266,7 +5308,7 @@ public TableDefinitionPart? TableDefinitionPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.VolatileType" /> <c>&lt;x:volType></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class VolatileTypes : OpenXmlPartRootElement
+    public partial class VolatileTypes : OpenXmlPartRootElement, IExtensionChildrenParent<VolatileTypes>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "volTypes");
@@ -5305,6 +5347,9 @@ public VolatileTypes(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5381,7 +5426,7 @@ public VolatileDependenciesPart? VolatileDependenciesPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2013.ExcelAc.AbsolutePath" /> <c>&lt;x15ac:absPath></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Workbook : OpenXmlPartRootElement
+    public partial class Workbook : OpenXmlPartRootElement, IExtensionChildrenParent<Workbook>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "workbook");
@@ -5430,6 +5475,9 @@ public EnumValue<DocumentFormat.OpenXml.Spreadsheet.ConformanceClass>? Conforman
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5726,7 +5774,7 @@ public WorkbookPart? WorkbookPart
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.IconFilter" /> <c>&lt;x14:iconFilter></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FilterColumn : OpenXmlCompositeElement
+    public partial class FilterColumn : OpenXmlCompositeElement, IExtensionChildrenParent<FilterColumn>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "filterColumn");
@@ -5795,6 +5843,9 @@ public BooleanValue? ShowButton
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -5963,7 +6014,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Office2010.Excel.SortCondition" /> <c>&lt;x14:sortCondition></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SortState : OpenXmlCompositeElement
+    public partial class SortState : OpenXmlCompositeElement, IExtensionChildrenParent<SortState>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sortState");
@@ -6042,6 +6093,9 @@ public StringValue? Reference
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -7741,7 +7795,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.WebQueryProperties" /> <c>&lt;x:webPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Connection : OpenXmlCompositeElement
+    public partial class Connection : OpenXmlCompositeElement, IExtensionChildrenParent<Connection>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "connection");
@@ -7980,6 +8034,9 @@ public StringValue? SingleSignOnId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -8540,7 +8597,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.MemberPropertiesMap" /> <c>&lt;x:mpMap></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CacheField : OpenXmlCompositeElement
+    public partial class CacheField : OpenXmlCompositeElement, IExtensionChildrenParent<CacheField>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cacheField");
@@ -8709,6 +8766,9 @@ public BooleanValue? MemberPropertyField
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -10872,7 +10932,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.Groups" /> <c>&lt;x:groups></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class GroupLevel : OpenXmlCompositeElement
+    public partial class GroupLevel : OpenXmlCompositeElement, IExtensionChildrenParent<GroupLevel>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "groupLevel");
@@ -10951,6 +11011,9 @@ public BooleanValue? CustomRollUp
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12046,7 +12109,7 @@ public DocumentFormat.OpenXml.Spreadsheet.Tuples? Tuples
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotArea" /> <c>&lt;x:pivotArea></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CalculatedItem : OpenXmlCompositeElement
+    public partial class CalculatedItem : OpenXmlCompositeElement, IExtensionChildrenParent<CalculatedItem>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "calculatedItem");
@@ -12105,6 +12168,9 @@ public StringValue? Formula
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12163,7 +12229,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotAreaReferences" /> <c>&lt;x:references></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotArea : OpenXmlCompositeElement
+    public partial class PivotArea : OpenXmlCompositeElement, IExtensionChildrenParent<PivotArea>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotArea");
@@ -12322,6 +12388,9 @@ public UInt32Value? FieldPosition
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12390,7 +12459,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.CalculatedMemberExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CalculatedMember : OpenXmlCompositeElement
+    public partial class CalculatedMember : OpenXmlCompositeElement, IExtensionChildrenParent<CalculatedMember>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "calculatedMember");
@@ -12499,6 +12568,9 @@ public BooleanValue? Set
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -12563,7 +12635,7 @@ public DocumentFormat.OpenXml.Spreadsheet.CalculatedMemberExtensionList? Calcula
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotFieldExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotField : OpenXmlCompositeElement
+    public partial class PivotField : OpenXmlCompositeElement, IExtensionChildrenParent<PivotField>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotField");
@@ -13082,6 +13154,9 @@ public BooleanValue? DefaultAttributeDrillState
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13356,7 +13431,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.DataFieldExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DataField : OpenXmlCompositeElement
+    public partial class DataField : OpenXmlCompositeElement, IExtensionChildrenParent<DataField>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "dataField");
@@ -13465,6 +13540,9 @@ public UInt32Value? NumberFormatId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13663,7 +13741,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotArea" /> <c>&lt;x:pivotArea></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Format : OpenXmlCompositeElement
+    public partial class Format : OpenXmlCompositeElement, IExtensionChildrenParent<Format>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "format");
@@ -13722,6 +13800,9 @@ public UInt32Value? FormatId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -13781,7 +13862,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotAreas" /> <c>&lt;x:pivotAreas></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormat : OpenXmlCompositeElement
+    public partial class ConditionalFormat : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "conditionalFormat");
@@ -13850,6 +13931,9 @@ public UInt32Value? Priority
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14109,7 +14193,7 @@ public DocumentFormat.OpenXml.Spreadsheet.PivotArea? PivotArea
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotHierarchyExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotHierarchy : OpenXmlCompositeElement
+    public partial class PivotHierarchy : OpenXmlCompositeElement, IExtensionChildrenParent<PivotHierarchy>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pivotHierarchy");
@@ -14258,6 +14342,9 @@ public StringValue? Caption
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -14803,7 +14890,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.PivotFilterExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotFilter : OpenXmlCompositeElement
+    public partial class PivotFilter : OpenXmlCompositeElement, IExtensionChildrenParent<PivotFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "filter");
@@ -14952,6 +15039,9 @@ public StringValue? StringValue2
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -15033,7 +15123,7 @@ public DocumentFormat.OpenXml.Spreadsheet.PivotFilterExtensionList? PivotFilterE
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.GroupLevels" /> <c>&lt;x:groupLevels></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CacheHierarchy : OpenXmlCompositeElement
+    public partial class CacheHierarchy : OpenXmlCompositeElement, IExtensionChildrenParent<CacheHierarchy>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cacheHierarchy");
@@ -15292,6 +15382,9 @@ public BooleanValue? Hidden
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -15685,7 +15778,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PageField : OpenXmlCompositeElement
+    public partial class PageField : OpenXmlCompositeElement, IExtensionChildrenParent<PageField>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "pageField");
@@ -15774,6 +15867,9 @@ public StringValue? Caption
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -15902,7 +15998,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.FieldItem" /> <c>&lt;x:x></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class PivotAreaReference : OpenXmlCompositeElement
+    public partial class PivotAreaReference : OpenXmlCompositeElement, IExtensionChildrenParent<PivotAreaReference>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "reference");
@@ -16111,6 +16207,9 @@ public BooleanValue? ApplyVariancePInSubtotal
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -16357,7 +16456,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QueryTableField : OpenXmlCompositeElement
+    public partial class QueryTableField : OpenXmlCompositeElement, IExtensionChildrenParent<QueryTableField>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "queryTableField");
@@ -16466,6 +16565,9 @@ public UInt32Value? TableColumnId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -17976,7 +18078,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SheetIdMap" /> <c>&lt;x:sheetIdMap></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Header : OpenXmlCompositeElement
+    public partial class Header : OpenXmlCompositeElement, IExtensionChildrenParent<Header>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "header");
@@ -18088,6 +18190,9 @@ public UInt32Value? MaxRevisionId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18580,7 +18685,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevisionSheetName : OpenXmlCompositeElement
+    public partial class RevisionSheetName : OpenXmlCompositeElement, IExtensionChildrenParent<RevisionSheetName>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "rsnm");
@@ -18679,6 +18784,9 @@ public StringValue? NewName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -18853,7 +18961,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NewCell" /> <c>&lt;x:nc></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevisionCellChange : OpenXmlCompositeElement
+    public partial class RevisionCellChange : OpenXmlCompositeElement, IExtensionChildrenParent<RevisionCellChange>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "rcc");
@@ -19032,6 +19140,9 @@ public BooleanValue? EndOfListFormulaUpdate
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19154,7 +19265,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevisionFormat : OpenXmlCompositeElement
+    public partial class RevisionFormat : OpenXmlCompositeElement, IExtensionChildrenParent<RevisionFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "rfmt");
@@ -19253,6 +19364,9 @@ public UInt32Value? Length
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -19461,7 +19575,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.OldFormula" /> <c>&lt;x:oldFormula></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class RevisionDefinedName : OpenXmlCompositeElement
+    public partial class RevisionDefinedName : OpenXmlCompositeElement, IExtensionChildrenParent<RevisionDefinedName>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "rdn");
@@ -19740,6 +19854,9 @@ public StringValue? OldComment
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20541,7 +20658,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.CellValue" /> <c>&lt;x:v></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OldCell : CellType
+    public partial class OldCell : CellType, IExtensionChildrenParent<OldCell>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "oc");
@@ -20580,6 +20697,9 @@ public OldCell(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20614,7 +20734,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.CellValue" /> <c>&lt;x:v></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Cell : CellType
+    public partial class Cell : CellType, IExtensionChildrenParent<Cell>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "c");
@@ -20653,6 +20773,9 @@ public Cell(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20693,7 +20816,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.CellValue" /> <c>&lt;x:v></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class CellType : OpenXmlCompositeElement
+    public abstract partial class CellType : OpenXmlCompositeElement, IExtensionChildrenParent<CellType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -20792,6 +20915,9 @@ public BooleanValue? ShowPhonetic
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -20875,7 +21001,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.CellValue" /> <c>&lt;x:v></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NewCell : OpenXmlCompositeElement
+    public partial class NewCell : OpenXmlCompositeElement, IExtensionChildrenParent<NewCell>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "nc");
@@ -20974,6 +21100,9 @@ public BooleanValue? ShowPhonetic
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21077,7 +21206,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class OldDifferentialFormat : DifferentialFormatType
+    public partial class OldDifferentialFormat : DifferentialFormatType, IExtensionChildrenParent<OldDifferentialFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "odxf");
@@ -21116,6 +21245,9 @@ public OldDifferentialFormat(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21153,7 +21285,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class NewDifferentialFormat : DifferentialFormatType
+    public partial class NewDifferentialFormat : DifferentialFormatType, IExtensionChildrenParent<NewDifferentialFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "ndxf");
@@ -21192,6 +21324,9 @@ public NewDifferentialFormat(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21229,7 +21364,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class DifferentialFormat : DifferentialFormatType
+    public partial class DifferentialFormat : DifferentialFormatType, IExtensionChildrenParent<DifferentialFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "dxf");
@@ -21268,6 +21403,9 @@ public DifferentialFormat(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21305,7 +21443,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.NumberingFormat" /> <c>&lt;x:numFmt></c></description></item>
     /// </list>
     /// </remarks>
-    public abstract partial class DifferentialFormatType : OpenXmlCompositeElement
+    public abstract partial class DifferentialFormatType : OpenXmlCompositeElement, IExtensionChildrenParent<DifferentialFormatType>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new(string.Empty, string.Empty);
@@ -21344,6 +21482,9 @@ protected DifferentialFormatType(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21697,7 +21838,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class UserInfo : OpenXmlCompositeElement
+    public partial class UserInfo : OpenXmlCompositeElement, IExtensionChildrenParent<UserInfo>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "userInfo");
@@ -21776,6 +21917,9 @@ public DateTimeValue? DateTime
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -21834,7 +21978,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class Row : OpenXmlCompositeElement
+    public partial class Row : OpenXmlCompositeElement, IExtensionChildrenParent<Row>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "row");
@@ -22006,6 +22150,9 @@ public DoubleValue? DyDescent
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23791,7 +23938,7 @@ public DocumentFormat.OpenXml.Spreadsheet.FirstFooter? FirstFooter
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SortState" /> <c>&lt;x:sortState></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class AutoFilter : OpenXmlCompositeElement
+    public partial class AutoFilter : OpenXmlCompositeElement, IExtensionChildrenParent<AutoFilter>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "autoFilter");
@@ -23840,6 +23987,9 @@ public StringValue? Reference
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -23876,7 +24026,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.Formula" /> <c>&lt;x:formula></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormattingRule : OpenXmlCompositeElement
+    public partial class ConditionalFormattingRule : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormattingRule>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cfRule");
@@ -24045,6 +24195,9 @@ public BooleanValue? EqualAverage
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -24198,7 +24351,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormatValueObject : OpenXmlCompositeElement
+    public partial class ConditionalFormatValueObject : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormatValueObject>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cfvo");
@@ -24267,6 +24420,9 @@ public BooleanValue? GreaterThanOrEqual
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -25039,7 +25195,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartSheetView : OpenXmlCompositeElement
+    public partial class ChartSheetView : OpenXmlCompositeElement, IExtensionChildrenParent<ChartSheetView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sheetView");
@@ -25118,6 +25274,9 @@ public BooleanValue? ZoomToFit
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -26003,7 +26162,7 @@ public DocumentFormat.OpenXml.Spreadsheet.Formula2? Formula2
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.Selection" /> <c>&lt;x:selection></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SheetView : OpenXmlCompositeElement
+    public partial class SheetView : OpenXmlCompositeElement, IExtensionChildrenParent<SheetView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sheetView");
@@ -26232,6 +26391,9 @@ public UInt32Value? WorkbookViewId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -26315,7 +26477,7 @@ public DocumentFormat.OpenXml.Spreadsheet.Pane? Pane
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.Selection" /> <c>&lt;x:selection></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CustomSheetView : OpenXmlCompositeElement
+    public partial class CustomSheetView : OpenXmlCompositeElement, IExtensionChildrenParent<CustomSheetView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "customSheetView");
@@ -26554,6 +26716,9 @@ public StringValue? TopLeftCell
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27156,7 +27321,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.FutureMetadataBlock" /> <c>&lt;x:bk></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FutureMetadata : OpenXmlCompositeElement
+    public partial class FutureMetadata : OpenXmlCompositeElement, IExtensionChildrenParent<FutureMetadata>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "futureMetadata");
@@ -27215,6 +27380,9 @@ public UInt32Value? Count
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -27925,7 +28093,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class FutureMetadataBlock : OpenXmlCompositeElement
+    public partial class FutureMetadataBlock : OpenXmlCompositeElement, IExtensionChildrenParent<FutureMetadataBlock>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "bk");
@@ -27964,6 +28132,9 @@ public FutureMetadataBlock(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28653,7 +28824,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.XmlCellProperties" /> <c>&lt;x:xmlCellPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SingleXmlCell : OpenXmlCompositeElement
+    public partial class SingleXmlCell : OpenXmlCompositeElement, IExtensionChildrenParent<SingleXmlCell>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "singleXmlCell");
@@ -28722,6 +28893,9 @@ public UInt32Value? ConnectionId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28793,7 +28967,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.XmlProperties" /> <c>&lt;x:xmlPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class XmlCellProperties : OpenXmlCompositeElement
+    public partial class XmlCellProperties : OpenXmlCompositeElement, IExtensionChildrenParent<XmlCellProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "xmlCellPr");
@@ -28852,6 +29026,9 @@ public StringValue? UniqueName
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -28918,7 +29095,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class XmlProperties : OpenXmlCompositeElement
+    public partial class XmlProperties : OpenXmlCompositeElement, IExtensionChildrenParent<XmlProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "xmlPr");
@@ -28987,6 +29164,9 @@ public EnumValue<DocumentFormat.OpenXml.Spreadsheet.XmlDataValues>? XmlDataType
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -30560,7 +30740,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CellStyle : OpenXmlCompositeElement
+    public partial class CellStyle : OpenXmlCompositeElement, IExtensionChildrenParent<CellStyle>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cellStyle");
@@ -30659,6 +30839,9 @@ public BooleanValue? CustomBuiltin
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -30715,7 +30898,7 @@ public DocumentFormat.OpenXml.Spreadsheet.ExtensionList? ExtensionList
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CellFormat : OpenXmlCompositeElement
+    public partial class CellFormat : OpenXmlCompositeElement, IExtensionChildrenParent<CellFormat>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "xf");
@@ -30884,6 +31067,9 @@ public BooleanValue? ApplyProtection
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32437,7 +32623,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.XmlColumnProperties" /> <c>&lt;x:xmlColumnPr></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TableColumn : OpenXmlCompositeElement
+    public partial class TableColumn : OpenXmlCompositeElement, IExtensionChildrenParent<TableColumn>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "tableColumn");
@@ -32596,6 +32782,9 @@ public StringValue? TotalsRowCellStyle
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -32864,7 +33053,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class XmlColumnProperties : OpenXmlCompositeElement
+    public partial class XmlColumnProperties : OpenXmlCompositeElement, IExtensionChildrenParent<XmlColumnProperties>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "xmlColumnPr");
@@ -32943,6 +33132,9 @@ public EnumValue<DocumentFormat.OpenXml.Spreadsheet.XmlDataValues>? XmlDataType
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -33539,7 +33731,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CustomWorkbookView : OpenXmlCompositeElement
+    public partial class CustomWorkbookView : OpenXmlCompositeElement, IExtensionChildrenParent<CustomWorkbookView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "customWorkbookView");
@@ -33818,6 +34010,9 @@ public EnumValue<DocumentFormat.OpenXml.Spreadsheet.ObjectDisplayValues>? ShowOb
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -33991,7 +34186,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class WorkbookView : OpenXmlCompositeElement
+    public partial class WorkbookView : OpenXmlCompositeElement, IExtensionChildrenParent<WorkbookView>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "workbookView");
@@ -34160,6 +34355,9 @@ public BooleanValue? AutoFilterDateGrouping
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -36500,7 +36698,7 @@ public DocumentFormat.OpenXml.Spreadsheet.TabColor? TabColor
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ChartSheetViews : OpenXmlCompositeElement
+    public partial class ChartSheetViews : OpenXmlCompositeElement, IExtensionChildrenParent<ChartSheetViews>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sheetViews");
@@ -36539,6 +36737,9 @@ public ChartSheetViews(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -37905,7 +38106,7 @@ public DocumentFormat.OpenXml.Spreadsheet.PageSetupProperties? PageSetupProperti
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SheetView" /> <c>&lt;x:sheetView></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class SheetViews : OpenXmlCompositeElement
+    public partial class SheetViews : OpenXmlCompositeElement, IExtensionChildrenParent<SheetViews>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "sheetViews");
@@ -37944,6 +38145,9 @@ public SheetViews(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -38904,7 +39108,7 @@ public DocumentFormat.OpenXml.Spreadsheet.DataReferences? DataReferences
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.ExtensionList" /> <c>&lt;x:extLst></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class ConditionalFormatting : OpenXmlCompositeElement
+    public partial class ConditionalFormatting : OpenXmlCompositeElement, IExtensionChildrenParent<ConditionalFormatting>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "conditionalFormatting");
@@ -38963,6 +39167,9 @@ public ListValue<StringValue>? SequenceOfReferences
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -43154,7 +43361,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.SortState" /> <c>&lt;x:sortState></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class QueryTableRefresh : OpenXmlCompositeElement
+    public partial class QueryTableRefresh : OpenXmlCompositeElement, IExtensionChildrenParent<QueryTableRefresh>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "queryTableRefresh");
@@ -43263,6 +43470,9 @@ public UInt32Value? UnboundColumnsRight
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -43951,7 +44161,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.IgnoredError" /> <c>&lt;x:ignoredError></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class IgnoredErrors : OpenXmlCompositeElement
+    public partial class IgnoredErrors : OpenXmlCompositeElement, IExtensionChildrenParent<IgnoredErrors>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "ignoredErrors");
@@ -43990,6 +44200,9 @@ public IgnoredErrors(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -46689,7 +46902,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.WorksheetSource" /> <c>&lt;x:worksheetSource></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class CacheSource : OpenXmlCompositeElement
+    public partial class CacheSource : OpenXmlCompositeElement, IExtensionChildrenParent<CacheSource>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "cacheSource");
@@ -46748,6 +46961,9 @@ public UInt32Value? ConnectionId
             set => SetAttribute(value);
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
@@ -47060,7 +47276,7 @@ internal override void ConfigureMetadata(ElementMetadata.Builder builder)
     ///   <item><description><see cref="DocumentFormat.OpenXml.Spreadsheet.Sets" /> <c>&lt;x:sets></c></description></item>
     /// </list>
     /// </remarks>
-    public partial class TupleCache : OpenXmlCompositeElement
+    public partial class TupleCache : OpenXmlCompositeElement, IExtensionChildrenParent<TupleCache>
     {
         #pragma warning disable CS0109
         internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/spreadsheetml/2006/main", "tupleCache");
@@ -47099,6 +47315,9 @@ public TupleCache(string outerXml) : base(outerXml)
         {
         }
 
+        public static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>() {
+        };
+        
         internal override void ConfigureMetadata(ElementMetadata.Builder builder)
         {
             base.ConfigureMetadata(builder);
diff --git a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlNamespace.cs b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlNamespace.cs
index ad4675aac..76307d57b 100644
--- a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlNamespace.cs
+++ b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlNamespace.cs
@@ -11,7 +11,7 @@ namespace DocumentFormat.OpenXml.Framework;
 /// </summary>
 [Experimental(ExperimentalApis.Framework, UrlFormat = ExperimentalApis.UrlFormat)]
 [Obsolete(ExperimentalApis.Message, DiagnosticId = ExperimentalApis.Framework, UrlFormat = ExperimentalApis.UrlFormat)]
-internal readonly partial struct OpenXmlNamespace : IComparable<OpenXmlNamespace>, IEquatable<OpenXmlNamespace>
+public readonly partial struct OpenXmlNamespace : IComparable<OpenXmlNamespace>, IEquatable<OpenXmlNamespace>
 {
     private readonly string? _uri;
 
diff --git a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlQualifiedName.cs b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlQualifiedName.cs
index bb18d4b00..93cbfe48f 100644
--- a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlQualifiedName.cs
+++ b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlQualifiedName.cs
@@ -11,7 +11,7 @@ namespace DocumentFormat.OpenXml.Framework;
 /// </summary>
 [Experimental(ExperimentalApis.Framework, UrlFormat = ExperimentalApis.UrlFormat)]
 [Obsolete(ExperimentalApis.Message, DiagnosticId = ExperimentalApis.Framework, UrlFormat = ExperimentalApis.UrlFormat)]
-internal readonly struct OpenXmlQualifiedName : IComparable<OpenXmlQualifiedName>, IEquatable<OpenXmlQualifiedName>
+public readonly struct OpenXmlQualifiedName : IComparable<OpenXmlQualifiedName>, IEquatable<OpenXmlQualifiedName>
 {
     private readonly string? _name;
 
diff --git a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlSchemaType.cs b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlSchemaType.cs
index 6e5cbbddd..e95d14250 100644
--- a/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlSchemaType.cs
+++ b/src/DocumentFormat.OpenXml.Framework/Framework/OpenXmlSchemaType.cs
@@ -5,7 +5,7 @@
 
 namespace DocumentFormat.OpenXml.Framework;
 
-internal readonly struct OpenXmlSchemaType(OpenXmlQualifiedName name, OpenXmlQualifiedName type) : IComparable<OpenXmlSchemaType>, IEquatable<OpenXmlSchemaType>
+public readonly struct OpenXmlSchemaType(OpenXmlQualifiedName name, OpenXmlQualifiedName type) : IComparable<OpenXmlSchemaType>, IEquatable<OpenXmlSchemaType>
 {
     public OpenXmlQualifiedName Name => name;
 
diff --git a/src/DocumentFormat.OpenXml.Framework/OpenXmlCompositeElement.cs b/src/DocumentFormat.OpenXml.Framework/OpenXmlCompositeElement.cs
index 9a7312433..690f44d5e 100644
--- a/src/DocumentFormat.OpenXml.Framework/OpenXmlCompositeElement.cs
+++ b/src/DocumentFormat.OpenXml.Framework/OpenXmlCompositeElement.cs
@@ -177,8 +177,18 @@ public override string InnerXml
             }
         }
 
+
         #endregion
 
+//        #region static properties
+//        internal static IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; } = new List<OpenXmlSchemaType>();
+
+//#if NET8_0_OR_GREATER
+//        internal static IEnumerable<OpenXmlSchemaType> GetExtensionChildren()
+//            => ExtensionChildren;
+//#endif
+//        #endregion
+
         #region change children
 
         /// <summary>
diff --git a/src/DocumentFormat.OpenXml/Schema/Presentation/IExtensionChildrenParent.cs b/src/DocumentFormat.OpenXml/Schema/Presentation/IExtensionChildrenParent.cs
new file mode 100644
index 000000000..26bd1aad5
--- /dev/null
+++ b/src/DocumentFormat.OpenXml/Schema/Presentation/IExtensionChildrenParent.cs
@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using DocumentFormat.OpenXml.Framework;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace DocumentFormat.OpenXml.Packaging;
+
+public interface IExtensionChildrenParent<T>
+    where T : IExtensionChildrenParent<T>
+{
+#if NET8_0_OR_GREATER
+    public static abstract IEnumerable<OpenXmlSchemaType> ExtensionChildren { get; }
+
+    public IEnumerable<OpenXmlSchemaType> GetExtensionChildren()
+        => T.ExtensionChildren;
+#endif
+}
diff --git a/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtension.cs b/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtension.cs
new file mode 100644
index 000000000..6becbc11e
--- /dev/null
+++ b/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtension.cs
@@ -0,0 +1,128 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using DocumentFormat.OpenXml.Framework;
+using DocumentFormat.OpenXml.Framework.Metadata;
+using DocumentFormat.OpenXml.Packaging;
+using DocumentFormat.OpenXml.Validation.Schema;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+
+namespace DocumentFormat.OpenXml.Presentation;
+
+/// <summary>
+/// Represents an extension element in a PresentationML document.
+/// </summary>
+/// <typeparam name="T">
+/// The type of the extension content. This allows the <c>Extension&lt;T&gt;</c> element to encapsulate any valid Open XML element as its child,
+/// enabling support for custom or future extensions within the presentation schema.
+/// </typeparam>
+/// <remarks>
+/// The <c>Extension&lt;T&gt;</c> element is used to store additional information that is not defined in the standard schema,
+/// typically for custom features or forward compatibility. The required <c>Uri</c> attribute identifies the type or purpose of the extension.
+/// </remarks>
+public partial class Extension<T> : OpenXmlCompositeElement
+where T : IExtensionChildrenParent<T>
+{
+#pragma warning disable CS0109
+    internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "ext");
+    internal static readonly new OpenXmlQualifiedName ElementTypeName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "CT_Extension");
+    internal static readonly new OpenXmlSchemaType ElementType = new(ElementQName, ElementTypeName);
+#pragma warning restore CS0109
+
+    /// <summary>
+    /// Initializes a new instance of the Extension class.
+    /// </summary>
+    public Extension()
+        : base()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the Extension class with the specified child elements.
+    /// </summary>
+    /// <param name="childElements">Specifies the child elements.</param>
+    public Extension(IEnumerable<OpenXmlElement> childElements)
+        : base(childElements)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the Extension class with the specified child elements.
+    /// </summary>
+    /// <param name="childElements">Specifies the child elements.</param>
+    public Extension(params OpenXmlElement[] childElements)
+        : base(childElements)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the Extension class from outer XML.
+    /// </summary>
+    /// <param name="outerXml">Specifies the outer XML of the element.</param>
+    public Extension(string outerXml)
+        : base(outerXml)
+    {
+    }
+
+    /// <summary>
+    /// <para>Gets or sets uRI</para>
+    /// <para>Represents the following attribute in the schema: uri</para>
+    /// </summary>
+    public StringValue? Uri
+    {
+        get => GetAttribute<StringValue>();
+        set => SetAttribute(value);
+    }
+
+    internal override void ConfigureMetadata(ElementMetadata.Builder builder)
+    {
+        //      [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(
+        //System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicProperties |
+        //System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.NonPublicProperties)]
+        //Type tType = typeof(T);
+
+        IEnumerable<OpenXmlSchemaType>? val;
+
+#if NET8_0_OR_GREATER
+        val = T.ExtensionChildren;
+#else
+        val = (IEnumerable<OpenXmlSchemaType>?)typeof(T).GetProperty("ExtensionChildren", BindingFlags.NonPublic | BindingFlags.Static)?.GetValue(null);
+#endif
+        Console.WriteLine("method is running");
+        if (System.Diagnostics.Debugger.IsAttached)
+        {
+            System.Diagnostics.Debugger.Break();
+        }
+        else
+        {
+            System.Diagnostics.Debugger.Launch(); // Optionally launch the debugger if not attached
+        }
+
+        if (val is not null)
+        {
+            foreach (var type in val)
+            {
+                Console.WriteLine($"Adding child type: {type.Name}");
+            }
+        }
+
+        base.ConfigureMetadata(builder);
+        builder.SetSchema(ElementType);
+        builder.AddElement<Extension>()
+            .AddAttribute("uri", a => a.Uri, aBuilder =>
+            {
+                aBuilder.AddValidator(RequiredValidator.Instance);
+                aBuilder.AddValidator(new StringValidator() { IsToken = true });
+            });
+        builder.Particle = new CompositeParticle.Builder(ParticleType.Sequence, 1, 1)
+            {
+                new AnyParticle(1, 1),
+            };
+    }
+
+    /// <inheritdoc/>
+    public override OpenXmlElement CloneNode(bool deep) => CloneImp<Extension>(deep);
+}
diff --git a/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtensionList.cs b/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtensionList.cs
new file mode 100644
index 000000000..0b5752b6b
--- /dev/null
+++ b/src/DocumentFormat.OpenXml/Schema/Presentation/PresentationExtensionList.cs
@@ -0,0 +1,92 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using DocumentFormat.OpenXml.Framework;
+using DocumentFormat.OpenXml.Framework.Metadata;
+using DocumentFormat.OpenXml.Packaging;
+using DocumentFormat.OpenXml.Validation.Schema;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+
+namespace DocumentFormat.OpenXml.Presentation;
+
+/// <summary>
+/// Represents a list of extension elements (<c>extLst</c>) in a PresentationML document.
+/// </summary>
+/// <typeparam name="T">
+/// The type of extension element contained in the list. This allows the <c>ExtensionList&lt;T&gt;</c> to encapsulate any valid Open XML extension element,
+/// enabling support for custom or future extensions within the presentation schema.
+/// </typeparam>
+/// <remarks>
+/// The <c>ExtensionList&lt;T&gt;</c> element is used to store additional information that is not defined in the standard schema,
+/// typically for custom features or forward compatibility. Each child element is an <c>Extension</c> element.
+/// </remarks>
+#pragma warning disable SA1649 // File name should match first type name
+public class ExtensionList<T> : OpenXmlCompositeElement
+    where T : IExtensionChildrenParent<T>
+
+#pragma warning restore SA1649 // File name should match first type name
+{
+#pragma warning disable CS0109
+    internal static readonly new OpenXmlQualifiedName ElementQName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "extLst");
+    internal static readonly new OpenXmlQualifiedName ElementTypeName = new("http://schemas.openxmlformats.org/presentationml/2006/main", "CT_ExtensionList");
+    internal static readonly new OpenXmlSchemaType ElementType = new(ElementQName, ElementTypeName);
+#pragma warning restore CS0109
+
+    /// <summary>
+    /// Initializes a new instance of the ExtensionList class.
+    /// </summary>
+    public ExtensionList()
+        : base()
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the ExtensionList class with the specified child elements.
+    /// </summary>
+    /// <param name="childElements">Specifies the child elements.</param>
+    public ExtensionList(IEnumerable<OpenXmlElement> childElements)
+        : base(childElements)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the ExtensionList class with the specified child elements.
+    /// </summary>
+    /// <param name="childElements">Specifies the child elements.</param>
+    public ExtensionList(params OpenXmlElement[] childElements)
+        : base(childElements)
+    {
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the ExtensionList class from outer XML.
+    /// </summary>
+    /// <param name="outerXml">Specifies the outer XML of the element.</param>
+    public ExtensionList(string outerXml)
+        : base(outerXml)
+    {
+    }
+
+    internal override void ConfigureMetadata(ElementMetadata.Builder builder)
+    {
+        base.ConfigureMetadata(builder);
+        builder.SetSchema(ElementType);
+        builder.AddChild(DocumentFormat.OpenXml.Presentation.Extension<T>.ElementType, static () => new DocumentFormat.OpenXml.Presentation.Extension<T>());
+        builder.Particle = new CompositeParticle.Builder(ParticleType.Sequence, 1, 1)
+            {
+                new CompositeParticle.Builder(ParticleType.Group, 0, 1)
+                {
+                    new CompositeParticle.Builder(ParticleType.Sequence, 1, 1)
+                    {
+                        new ElementParticle(DocumentFormat.OpenXml.Presentation.Extension<T>.ElementType, 0, 0),
+                    },
+                },
+            };
+    }
+
+    /// <inheritdoc/>
+    public override OpenXmlElement CloneNode(bool deep) => CloneImp<ExtensionList>(deep);
+}
diff --git a/src/DocumentFormat.OpenXml/Schema/Presentation/SlideId.cs b/src/DocumentFormat.OpenXml/Schema/Presentation/SlideId.cs
new file mode 100644
index 000000000..b86c3b6d8
--- /dev/null
+++ b/src/DocumentFormat.OpenXml/Schema/Presentation/SlideId.cs
@@ -0,0 +1,32 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+////using DocumentFormat.OpenXml;
+////using DocumentFormat.OpenXml.Drawing;
+////using DocumentFormat.OpenXml.Framework;
+////using DocumentFormat.OpenXml.Framework.Metadata;
+////using DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M03.Main;
+////using DocumentFormat.OpenXml.Office.PowerPoint.Y2022.M08.Main;
+////using DocumentFormat.OpenXml.Office.PowerPoint.Y2023.M02.Main;
+////using DocumentFormat.OpenXml.Office2010.Drawing;
+////using DocumentFormat.OpenXml.Office2010.PowerPoint;
+////using DocumentFormat.OpenXml.Office2013.PowerPoint;
+////using DocumentFormat.OpenXml.Office2021.PowerPoint.Comment;
+////using DocumentFormat.OpenXml.Packaging;
+////using DocumentFormat.OpenXml.Validation.Schema;
+////using DocumentFormat.OpenXml.Validation.Semantic;
+////using System;
+////using System.Collections.Generic;
+////using System.IO.Packaging;
+
+
+////namespace DocumentFormat.OpenXml.Presentation;
+
+////public partial class SlideId : OpenXmlCompositeElement
+////{
+////    public DocumentFormat.OpenXml.Presentation.ExtensionList<SlideId>? ExtensionListT
+////    {
+////        get => GetElement(DocumentFormat.OpenXml.Presentation.ExtensionList<SlideId>.ElementType) as DocumentFormat.OpenXml.Presentation.ExtensionList<SlideId>;
+////        set => SetElement(value, DocumentFormat.OpenXml.Presentation.ExtensionList<SlideId>.ElementType);
+////    }
+////}