def __init__(self, business_hours=None, weekends=(5,6), holidays=None):
        if business_hours is None:
            business_hours = (datetime.time(9), datetime.time(17))
        self.business_hours = business_hours

        # TODO: weekends should maybe be a generator or a callable returning True/False
        self.weekends = weekends

        self.holidays = holidays
        if callable(self.holidays) or self.holidays is None:
            self._holidaysGeneratorStart = None
            self._holidaysGenerator = None
            self._holidays = []
        else:
            self._holidays = self.holidays

        # HACK: pick an arbitrary date so we can do math with datetime.time objects
        arbitrary_date = datetime.datetime(2014, 1, 26)
        start = datetime.datetime.combine(arbitrary_date, business_hours[0])
        end = datetime.datetime.combine(arbitrary_date, business_hours[1])
        self.open_hours = start - end
dataset/ETHPy150Open seatgeek/businesstime/businesstime/__init__.py/BusinessTime.__init__/swapped operands of `-`