add javadoc to builder factory method

odata-client-generator/src/main/java/com/github/davidmoten/odata/client/generator/Generator.java

@@ -1196,6 +1196,14 @@ private void writeBuilder(Structure<?> t, String simpleClassName, Imports import
         }
         String builderSuffix = t.getBaseType() == null ? "" : simpleClassName;
 
+        p.format("\n%s/**", indent);
+        p.format("\n%s * Returns a builder which is used to create a new", indent); 
+        p.format("\n%s * instance of this class (given that this class is immutable).", indent);
+        p.format("\n%s *", indent);
+        p.format("\n%s * @return a new Builder for this class", indent);
+        p.format("\n%s */", indent);
+        p.format("\n%s// Suffix used on builder factory method to differentiate the method", indent);
+        p.format("\n%s// from static builder methods on superclasses", indent);
         p.format("\n%spublic static Builder builder%s() {\n", indent, builderSuffix);
         p.format("%sreturn new Builder();\n", indent.right());
         p.format("%s}\n", indent.left());

src/docs/FileAttachment.java

@@ -49,6 +49,14 @@ protected FileAttachment() {
         super();
     }
 
+    /**
+     * Returns a builder which is used to create a new
+     * instance of this class (given that this class is immutable).
+     *
+     * @return a new Builder for this class
+     */
+    // Suffix used on builder factory method to differentiate the method
+    // from static builder methods on superclasses
     public static Builder builderFileAttachment() {
         return new Builder();
     }