add comment for NewInstance override
diff --git a/src/compiler/csharp_generator.cc b/src/compiler/csharp_generator.cc
index 591e5ae..4815703 100644
--- a/src/compiler/csharp_generator.cc
+++ b/src/compiler/csharp_generator.cc
@@ -495,6 +495,9 @@
 
   // override NewInstance method
   out->Print(
+      "/// <summary>Creates a new instance of client from given "
+      "<c>ClientBaseConfiguration</c>.</summary>\n");
+  out->Print(
       "protected override $name$ NewInstance(ClientBaseConfiguration "
       "configuration)\n",
       "name", GetClientClassName(service));