const std::vector<std::string>& output_names,
               bool expect_failure = false) {
    ASSERT_EQ(func_, nullptr);
    const char** output_names_ptr = ToArray(output_names);
    func_ = TF_GraphToFunction(func_graph_, func_name_, false, num_opers,
                               num_opers == -1 ? nullptr : opers.data(),
                               inputs.size(), inputs.data(), outputs.size(),

  TF_Operation* feed = Placeholder(func_graph.get(), s.get());
  TF_Operation* neg = Neg(feed, func_graph.get(), s.get());

  TF_Output inputs[] = {{feed, 0}};
  TF_Output outputs[] = {{neg, 0}};
  *func = TF_GraphToFunction(func_graph.get(), name, append_hash, -1,
                             /*opers=*/nullptr, 1, inputs, 1, outputs,
                             /*output_names=*/nullptr,