code: def _prepare_sort_options(self, has_pk):
          sort_options = super(ExtendedCollectionManager, self)._prepare_sort_options(has_pk)
          if self._values:
              if not sort_options:
                  sort_options = {}
              sort_options['get'] = self._values['fields']['keys']
          if self._sort_by_sortedset_after:
              for key in ('get', 'store'):
                  if key in self._sort_by_sortedset:
                      del self._sort_by_sortedset[key]
              if sort_options and (not has_pk or self._want_score_value):
                  for key in ('get', 'store'):
                      if key in sort_options:
                          self._sort_by_sortedset[key] = sort_options.pop(key)
              if not sort_options:
                  sort_options = None
          return sort_options