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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def is_holiday(self, day, extra_holidays=None):
 """Return True if it's an holiday. In addition to the regular holidays, you can add exceptions. By providing ``extra_holidays``, you'll state that these dates **are** holidays, even if not in the regular calendar holidays (or weekends). """

        day = cleaned_date(day)

        if extra_holidays:
            extra_holidays = tuple(map(cleaned_date, extra_holidays))

        if extra_holidays and day in extra_holidays:
            return True

        return day in self.holidays_set(day.year)