code: def date_this_decade(self, before_today=True, after_today=False):
          
          today = date.today()
          this_decade_start = date(today.year - (today.year % 10), 1, 1)
          next_decade_start = date(this_decade_start.year + 10, 1, 1)
  
          if before_today and after_today:
              return self.date_between_dates(this_decade_start, next_decade_start)
          elif not before_today and after_today:
              return self.date_between_dates(today, next_decade_start)
          elif not after_today and before_today:
              return self.date_between_dates(this_decade_start, today)
          else:
              return today
docs: Gets a Date object for the decade year.
  
          :param before_today: include days in current decade before today
          :param after_today: include days in current decade after today
          :example Date('2012-04-04')
          :return Date