def reason(self, reason):
        """
        Sets the reason of this CreateRefundRequest.
        A description of the reason for the refund.  Default value: `Refund via API`

        :param reason: The reason of this CreateRefundRequest.
        :type: str
        """

        if reason is None:
            raise ValueError("Invalid value for `reason`, must not be `None`")
        if len(reason) > 192:
            raise ValueError("Invalid value for `reason`, length must be less than `192`")

        self._reason = reason
Sets the reason of this CreateRefundRequest.
        A description of the reason for the refund.  Default value: `Refund via API`

        :param reason: The reason of this CreateRefundRequest.
        :type: str