@payment_id.setter<EOL><INDENT>def payment_id(self, payment_id):<DEDENT>
self._payment_id = payment_id<EOL>
Sets the payment_id of this V1Refund.
A Square-issued ID associated with the refund. For single-tender refunds, payment_id is the ID of the original payment ID. For split-tender refunds, payment_id is the ID of the original tender. For exchange-based refunds (is_exchange == true), payment_id is the ID of the original payment ID even if the payment includes other tenders.

:param payment_id: The payment_id of this V1Refund.
:type: str