Add comment for TotalMarkedSequenceSymbolFrequencyCounter class

csharp/Platform.Data.Doublets/Sequences/Frequencies/Counters/TotalMarkedSequenceSymbolFrequencyCounter.cs

@@ -0,0 +1,26 @@
+using System.Runtime.CompilerServices;
+using Platform.Interfaces;
+
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+namespace Platform.Data.Doublets.Sequences.Frequencies.Counters
+{
+    /// <summary>
+    /// Counts total amount of sequences in which the symbol (link) is used.
+    /// </summary>
+    public class TotalMarkedSequenceSymbolFrequencyCounter<TLink> : ICounter<TLink, TLink>
+    {
+        private readonly ILinks<TLink> _links;
+        private readonly ICriterionMatcher<TLink> _markedSequenceMatcher;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TotalMarkedSequenceSymbolFrequencyCounter(ILinks<TLink> links, ICriterionMatcher<TLink> markedSequenceMatcher)
+        {
+            _links = links;
+            _markedSequenceMatcher = markedSequenceMatcher;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TLink Count(TLink argument) => new TotalMarkedSequenceSymbolFrequencyOneOffCounter<TLink>(_links, _markedSequenceMatcher, argument).Count();
+    }
+}