Petrov v. Gonzales, 464 F.3d 800, 2006 WL 2846451 (7th Cir. Oct. 6, 2006) ("Because Tunis did not mention that subject, it does not contain a holding on the issue. See Steel Co. v. Citizens for a Better Environment, 523 U.S. 83, 91, 118 S.Ct. 1003, 140 L.Ed.2d 210 (1998); United States v. L.A. Tucker Truck Lines, Inc., 344 U.S. 33, 38, 73 S.Ct. 67, 97 L.Ed. 54 (1952).").