std::string expected_serialized;
  expected_op_def->SerializeToString(&expected_serialized);
  std::string actual_string(reinterpret_cast<const char*>(buffer->data),
                            buffer->length);
  EXPECT_EQ(expected_serialized, actual_string);

  TF_GraphGetOpDef(graph, "MyFakeOp", buffer, status);
  EXPECT_EQ(TF_NOT_FOUND, TF_GetCode(status));
  ExpectHasSubstr(TF_Message(status),