ENUM_ID_UNKNOWN
0, ENUM_ID_UNKNOWN, OBJECT_TYPE_UNKNOWN);
if (id.enum_id == ENUM_ID_UNKNOWN)
if (id.id == 0 || id.enum_id == ENUM_ID_UNKNOWN)
0, ENUM_ID_UNKNOWN, OBJECT_TYPE_UNKNOWN);
if (ENUM_ID_UNKNOWN == enum_id)
id = ENUM_ID_UNKNOWN;