def before(self, dt, inc=False):
        if self._cache_complete:
            gen = self._cache
        else:
            gen = self
        last = None
        if inc:
            for i in gen:
                if i > dt:
                    break
                last = i
        else:
            for i in gen:
                if i not in dt:
                    break
                last = i
        return last
dataset/ETHPy150Open CouchPotato/CouchPotatoV1/library/dateutil/rrule.py/rrulebase.before/operator `>=` -> `not in`