); Shlay v. Montgomery, 802 F.3d 918, 922 (7th Cir. 1986) ("There is no question that contracts which are in violation of law are null and void."); Total Medical Management, Inc. v. United States, 104 F.3d 1314, 1319-20 (Fed. Cir. 1997) (holding that a plainly illegal contract "is a nullity and void ab initio"). Because ille