(a) A monetary claim is neither usurious nor unconscionable because the agreement on which it is based provides that the amount of the debtor's obligation to be paid in the debtor's money shall, when received by the creditor, equal a specified amount of the foreign money of the country of the creditor.
(b) If due to delay in payment, the amount of a judgment does not yield the required amount of the creditor's money, the obligation to pay an additional sum will support another action for the amount remaining unpaid, and that obligation is not merged in the judgment.