ther a taxpayer's accounting method clearly reflects income, and the Commissioner's determination must be upheld unless it is clearly unlawful. See Thor Power Tool Co. v. Commissioner, 439 U.S. 522, 532-3 (1979), RCA Corp. v. United States, 664 F.2d 881, 886 (2nd Cir. 1981). IRC § 481(a) requires those adjustments