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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 _end_of_decade(self):
 """ Reset the date to the last day of the decade. :rtype: Date """

        year = self.year - self.year % YEARS_PER_DECADE + YEARS_PER_DECADE - 1

        return self.set(year, 12, 31)