A term providing that one party or the party’s successor in interest may accelerate payment or performance or require collateral or additional collateral “at will” or “when she or he deems herself or himself insecure” or in words of similar import must be construed to mean that she or he has power to do so only if she or he in good faith believes that the prospect of payment or performance is impaired. The burden of establishing lack of good faith is on the party against whom the power has been exercised.