Do three things: (1) Make an argument that Alaska Packers' Association v. Domenico should come out the other way and the court should enforce the modification under section 89. (2) Make an argument that Levine v. Blumenthal should come out the other way and the court should enforce the modification under section 89. (3) Make an argument that Angel v. Murray should come out the other way and the court shouldn't enforce the modification.