code: def sort(self, **parameters):
          
          self._sort_by_sortedset = None
          is_sortedset = False
          if parameters.get('by_score'):
              if parameters.get('by'):
                  raise ValueError("You can't use `by` and `by_score` in the same "
                                   "call to `sort`.")
              by = parameters.get('by_score', None)
              if isinstance(by, SortedSetField) and getattr(by, '_instance', None):
                  by = by.key
              elif not isinstance(by, str):
                  by = None
  
              if by is None:
                  raise ValueError('To sort by sorted set, you must pass a '
                                   'SortedSetFied (attached to a model) or a '
                                   'string representing the key of a redis zset '
                                   'to the `by_score` named argument')
              is_sortedset = True
              parameters['by'] = by
              del parameters['by_score']
  
          else:
              # allow passing a field, not only a field name
              by = parameters.get('by')
              if by and isinstance(by, RedisField):
                  parameters['by'] = by.name
  
          super(ExtendedCollectionManager, self).sort(**parameters)
  
          if is_sortedset:
              self._sort_by_sortedset = self._sort
              self._sort = None
  
          return self
docs: Enhance the default sort method to accept a new parameter "by_score", to
          use instead of "by" if you want to sort by the score of a sorted set.
          You must pass to "by_sort" the key of a redis sorted set (or a
          sortedSetField attached to an instance)