def __init__(self, parent, target_cls):
        if target_cls != parent._clslevel:
            parent.update_subclass(target_cls)
        self.parent = parent  # _ClsLevelDispatch
        self.parent_listeners = parent._clslevel[target_cls]
        self.name = parent.name
dataset/ETHPy150Open zzzeek/sqlalchemy/lib/sqlalchemy/event/attr.py/_EmptyListener.__init__/operator `not in` -> `!=`