n10 Applying the principles recognized from Butner v. United States, "the determination of property rights in the assets [is left] to state law." 440 U.S. at 54 n.9, 99 S. Ct. at 918 n.9, 59 L. Ed. 2d at 141 n.9. McDonald discredits the position taken by other courts that legal retainers are always property of the estate without reference to state law. Cf. In re Hathaway Ranch Partnership, 116 Bankr. 208 (Bankr. C.D. Cal. 1990); In re C & P Auto Transport, Inc., 94 Bankr. 682 (Bankr. E.D. Cal. 1988); In re Kinderhaus Corp., 58 Bankr. 94 (Bankr. D. Minn. 1986).