Title 11, Chapter 1, Section 208
Option to accelerate at will.
A term providing that one party or his successor in interest may
accelerate payment or performance or require collateral or
additional collateral "at will" or "when he deems himself insecure"
or in words of similar import shall be construed to mean that he
shall have power to do so only if 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.