Check if a given date is a holiday.

        Args:
            date (date, datetime or str): Date to be checked.

        Returns:
            bool: True if the date is a holiday, False otherwise.

def isholiday(self, date):
        """
        Check if a given date is a holiday.

        Args:
            date (date, datetime or str): Date to be checked.

        Returns:
            bool: True if the date is a holiday, False otherwise.
        """
        date = parsefun(date)
        if self.holidays:
            # i is the index of first holiday >= date
            i = bisect.bisect_left(self.holidays, date)
            if i == 0 and date < self.holidays[0]:
                warn('Holiday list exhausted at start, ' \
                     'isholiday(%s) output may be incorrect.' % date)
            elif i == len(self.holidays):
                warn('Holiday list exhausted at end, ' \
                     'isholiday(%s) output may be incorrect.' % date)
            elif self.holidays[i] == date:
                return True
        return False