def get_once(sender, topic, *args, **kwargs):
    signal = kwargs.get('signal')
    if _called in (topic, signal):
        return _called[(topic, signal)]
    else:
        r = get(sender, topic, *args, **kwargs)
        _called[(topic, signal)] = r
        return r
dataset/ETHPy150Open limodou/uliweb/uliweb/core/dispatch.py/get_once/swapped operands of `in`