Added docstring to DeleteQuery.delete_qs()

            self.do_query(self.model._meta.db_table, where, using=using)

    def delete_qs(self, query, using):

        """

        Delete the queryset in one SQL query (if possible). For simple queries

        this is done by copying the query.query.where to self.query, for

        complex queries by using subquery.

        """

        innerq = query.query

        # Make sure the inner query has at least one table in use.

        innerq.get_initial_alias()