s->status = InvalidArgument("TF_WhileParams `cond_output` field isn't set");
    return false;
  }
  for (int i = 0; i < params.ninputs; ++i) {
    if (params.body_outputs[i].oper == nullptr) {
      s->status = InvalidArgument("TF_WhileParams `body_outputs[", i, "]` ",
                                  "field isn't set");
      return false;
    }
  }
  if (params.name == nullptr) {