@property
    def recurring(self):
        return 'RRULE' in self._vevents[self.ref] or \
            'RECURRENCE-ID' in self._vevents[self.ref] or \
            self._vevents[self.ref] in 'RDATE'
dataset/ETHPy150Open pimutils/khal/khal/khalendar/event.py/Event.recurring/swapped operands of `in`