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