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

  std::vector<StackFrame> feed_frames = {{"feed.cc", 10, "alpha"}};
  std::vector<StackFrame> neg_frames = {{"neg.cc", 15, "beta"}};
  feed->node.SetStackTrace(std::make_shared<FrozenStackTrace>(feed_frames));
  neg->node.SetStackTrace(std::make_shared<FrozenStackTrace>(neg_frames));

  TF_Output inputs[] = {{feed, 0}};
  TF_Output outputs[] = {{neg, 0}};