if (attr->list().field##_size() > 0) {              \
    metadata.type = attr_type;                        \
    metadata.list_size = attr->list().field##_size(); \
    __VA_ARGS__;                                      \
    break;                                            \
  }

      LIST_CASE(
          s, TF_ATTR_STRING, metadata.total_size = 0;