@classmethod
def is_placeholder(cls, code):
    """省直辖县级行政区划/自治区直辖县级行政区划。不属于正常地区，占位连接直辖县"""
    if code in ('156419000000000', '156429000000000', '156469000000000',
        '156659000000000'):
        return True
    return False
