TF_Status* status) {
  NameRangeMap name_ranges;
  status->status =
      NameRangesForNode(oper->node, oper->node.op_def(), nullptr, &name_ranges);
  if (!status->status.ok()) return -1;
  auto iter = name_ranges.find(arg_name);
  if (iter == name_ranges.end()) {
    status->status = InvalidArgument("Output arg '", arg_name, "' not found");
    return -1;
  }