出让人

In case both parties agree to let the alienator continuously possess the chattel when the real right of a chattel is alienated, the real right shall go into effect upon the effectiveness of the agreement.

动产权转让时，双方又约定由出让继续占有该动产，权自该约定生效时发生效力。

Normally, obligor can restitute only from the assignor if the creditor's right assigned doesn't exist or obligor revokes the contract.

让与债权不存在或者债务解除合同时,债务只能够向债权出让请求返还。