Extracted ICodedInputStream interface
diff --git a/src/ProtocolBuffers.Test/AbstractMessageTest.cs b/src/ProtocolBuffers.Test/AbstractMessageTest.cs
index e300ac9..f1dbda3 100644
--- a/src/ProtocolBuffers.Test/AbstractMessageTest.cs
+++ b/src/ProtocolBuffers.Test/AbstractMessageTest.cs
@@ -465,7 +465,7 @@
                     return this;

                 }

 

-                public override Builder MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry)

+                public override Builder MergeFrom(ICodedInputStream input, ExtensionRegistry extensionRegistry)

                 {

                     wrappedBuilder.WeakMergeFrom(input, extensionRegistry);

                     return this;