result.Append(std::move(pad));
    }
    AppendBufferData(result);
    std::string result_str = std::string(std::move(result));
    auto mutable_model = tflite::GetMutableModel(result_str.data());
    bool ret = UpdateBufferOffsets(mutable_model);
    if (!ret) {
      return std::nullopt;
    }
    return result_str;
  }
  return std::string(result);
}