// Add while loop to func_graph_
  {
    // The inputs to the while loop
    std::vector<TF_Output> inputs = {{feed1, 0}, {feed2, 0}};
    std::unique_ptr<TF_WhileParams> params(new TF_WhileParams(
        TF_NewWhile(func_graph_, &inputs[0], inputs.size(), s_)));
    ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);
    params->name = "test_loop";

    // Initialize outputs so we can easily detect errors/bugs