code: def _end_of_century(self):
          
          year = self.year - 1 - (self.year - 1) % YEARS_PER_CENTURY + YEARS_PER_CENTURY
  
          return self.set(year, 12, 31, 23, 59, 59, 999999)
docs: Reset the date to the last day of the century
          and the time to 23:59:59.999999.
  
          :rtype: DateTime