// Create default mocks, and return values for the code context position.
        void MockCodeContext(ulong address)
        {
            // Create mock code context with the specified address.
            var mockCodeContext = Substitute.For <IDebugCodeContext2>();

            System.Action <CONTEXT_INFO[]> setContextInfo = infos =>
            {
                infos[0].bstrAddress = "0x" + address.ToString("x16");
                infos[0].dwFields    = enum_CONTEXT_INFO_FIELDS.CIF_ADDRESS;
            };
            ((IDebugMemoryContext2)mockCodeContext)
            .GetInfo(Arg.Any <enum_CONTEXT_INFO_FIELDS>(), Arg.Do(setContextInfo))
            .Returns(VSConstants.S_OK);
            mockCodeContext
            .GetInfo(Arg.Any <enum_CONTEXT_INFO_FIELDS>(), Arg.Do(setContextInfo))
            .Returns(VSConstants.S_OK);

            mockMarshal.GetCodeContextFromIntPtr(Arg.Any <IntPtr>()).Returns(
                mockCodeContext);
        }