An agreement of the parties to a credit transaction concerning default by the borrower is enforceable only to the extent that:

1. (1) The borrower fails to make a payment as required by agreement; or
2. (2) The lender's prospect of payment, performance, or ability to realize upon the collateral is significantly impaired; the burden of establishing significant impairment is on the lender.

(L. 1979 S.B. 305)