discussed Cited "see" Boyer v. Conaboy See United States v. Damerville, 27 F.3d 254, 257 (7th Cir.) (holding that Commission’s decision to include conspiracy within its definition of "controlled substance offenses” was a valid exercise of its authority under 28 U.S.C. § 994 (a)), cert. denied, 513 U.S. 972 , 115 S.Ct. 445 , 130 L.Ed.2d 355 (1994). 5 .