EXPECT_EQ(string("feed"), string(TF_OperationName(feed)));
  EXPECT_EQ(string("Placeholder"), string(TF_OperationOpType(feed)));
  EXPECT_EQ(string(""), string(TF_OperationDevice(feed)));
  EXPECT_EQ(1, TF_OperationNumOutputs(feed));
  EXPECT_EQ(TF_INT32, TF_OperationOutputType(TF_Output{feed, 0}));
  EXPECT_EQ(1, TF_OperationOutputListLength(feed, "output", s));
  ASSERT_EQ(TF_OK, TF_GetCode(s)) << TF_Message(s);

  return oper->node.type_string().c_str();
}

const char* TF_OperationDevice(TF_Operation* oper) {
  return oper->node.requested_device().c_str();
}

int TF_OperationNumOutputs(TF_Operation* oper) {
  return oper->node.num_outputs();
}

TF_DataType TF_OperationOutputType(TF_Output oper_out) {
  return static_cast<TF_DataType>(