RunGraphsAndCompareOutputs(grad_outputs, expected_grad_outputs);
  }

  void TestGradientsError(bool grad_inputs_provided) {
    TF_Output inputs[1];
    TF_Output outputs[1];
    TF_Output grad_outputs[1];

    BuildErrorGraph(inputs, outputs);

    AddGradients(grad_inputs_provided, nullptr, inputs, 1, outputs, 1,
                 grad_outputs);

    std::string expected_msg =