grad_outputs);

    string expected_msg =
        "No gradient defined for op: TestOpWithNoGradient. Please see "
        "https://www.tensorflow.org/code/"
        "tensorflow/cc/gradients/README.md"
        " for instructions on how to add C++ gradients.";
    EXPECT_EQ(expected_msg, TF_Message(s_));
  }

  // Run the graph and ensure that the gradient values are as expected.

  // `modular_filesystem_test.h` and extend the instantiation to also take as
  // argument an implementation for this method/a subclass factory (see
  // https://github.com/google/googletest/blob/master/googletest/docs/advanced.md#creating-value-parameterized-abstract-tests)
  std::string GetURIForPath(StringPiece path) {
    const std::string translated_name =
        tensorflow::io::JoinPath(root_dir_, path);

//
// WARNING: This function does not yet support all the gradients that python
// supports. See
// https://www.tensorflow.org/code/tensorflow/cc/gradients/README.md
// for instructions on how to add C++ more gradients.
TF_CAPI_EXPORT void TF_AddGradients(TF_Graph* g, TF_Output* y, int ny,
                                    TF_Output* x, int nx, TF_Output* dx,