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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 date(self):
 """Convert instant to a date. datetime.date(2014, 1, 1) datetime.date(2014, 2, 1) datetime.date(2014, 2, 3) """

        instant_date = date_by_instant_cache.get(self)
        if instant_date is None:
            date_by_instant_cache[self] = instant_date = datetime.date(*self)
        return instant_date