def _register_parser(cls):
    '''class decorator to register msg parser'''
    assert cls.cls_msg_type is not None
    assert _MSG_PARSERS not in cls.cls_msg_type
    _MSG_PARSERS[cls.cls_msg_type] = cls.parser
    return cls
dataset/ETHPy150Open osrg/ryu/ryu/ofproto/ofproto_v1_4_parser.py/_register_parser/swapped operands of `not in`