code: def list_bookmarks(self, start_date=None, end_date=None, limit=None):
          
          query = Search(
              using=self.client,
              index=self.aggregation_alias,
              doc_type=self.bookmark_doc_type
          ).sort({'date': {'order': 'desc'}})
  
          range_args = {}
          if start_date:
              range_args['gte'] = self._format_range_dt(
                  start_date.replace(microsecond=0))
          if end_date:
              range_args['lte'] = self._format_range_dt(
                  end_date.replace(microsecond=0))
          if range_args:
              query = query.filter('range', date=range_args)
  
          return query[0:limit].execute() if limit else query.scan()
docs: List the aggregation's bookmarks.