listExt name

sorting/dotnet/Sorting/ListExt.cs

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Sorting
+{
+    public static class ListExt
+    {
+        public static string AsString(this List<int> list)
+        {
+            return "(" + string.Join(", ", list.Select(x => x.ToString())) + ")";
+        }
+    }
+}