@_generative(_no_clauseelement_condition)
    def with_polymorphic(self,
                         cls_or_mappers,
                         selectable=None,
                         polymorphic_on=None):

        if not self._primary_entity:
            raise sa_exc.InvalidRequestError(
                "No primary mapper set up for this Query.")
        entity = self._entities[0]._clone()
        self._entities = [entity] + self._entities[1:]
        entity.set_with_polymorphic(self,
                                    cls_or_mappers,
                                    selectable=selectable,
                                    polymorphic_on=polymorphic_on)
Load columns for inheriting classes.
dataset/ETHPy150Open goFrendiAsgard/kokoropy/kokoropy/packages/sqlalchemy/orm/query.py/Query.with_polymorphic