grads.emplace_back(grad.function_name(), grad.gradient_func());
  }
  std::sort(grads.begin(), grads.end());
  return grads;
}

std::vector<string> GetFuncNames(const tensorflow::GraphDef& graph_def) {
  std::vector<string> names;
  auto functions = graph_def.library().function();
  names.reserve(functions.size());
  for (const tensorflow::FunctionDef& func : functions) {

  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  // Verify that function and its grad are in host graph's GraphDef
  GraphDef gdef;
  GetGraphDef(host_graph_, &gdef);
  std::vector<string> func_names = GetFuncNames(gdef);
  ASSERT_EQ(2, func_names.size());
  ASSERT_EQ(func_name_, func_names[0]);
  ASSERT_EQ("MyGrad", func_names[1]);
  std::vector<std::pair<string, string>> grads = GetGradDefs(gdef);