Status s = oper_in.oper->node.input_edge(oper_in.index, &edge);
  if (!s.ok()) {
    return {nullptr, -1};
  }

  return {ToOperation(edge->src()), edge->src_output()};
}

void TF_OperationAllInputs(TF_Operation* oper, TF_Output* inputs,
                           int max_inputs) {
  for (auto* edge : oper->node.in_edges()) {
    if (edge->dst_input() >= 0 && edge->dst_input() < max_inputs) {