code: def end_of(self, unit):
          
          if unit not in self._MODIFIERS_VALID_UNITS:
              raise ValueError('Invalid unit "%s" for end_of()' % unit)
  
          return getattr(self, "_end_of_%s" % unit)()
docs: Returns a copy of the instance with the time reset
          with the following rules:
  
          * second: microsecond set to 999999
          * minute: second set to 59 and microsecond set to 999999
          * hour: minute and second set to 59 and microsecond set to 999999
          * day: time to 23:59:59.999999
          * week: date to last day of the week and time to 23:59:59.999999
          * month: date to last day of the month and time to 23:59:59.999999
          * year: date to last day of the year and time to 23:59:59.999999
          * decade: date to last day of the decade and time to 23:59:59.999999
          * century: date to last day of century and time to 23:59:59.999999
  
          :param unit: The unit to reset to
          :type unit: str
  
          :rtype: DateTime