What is the effect of a bankruptcy proceeding involving a claim against a bankrupt who also has a claim in state law?

substance rather than form of an asserted "core" proceeding, (8) the feasibility of severing state law claims from core bankruptcy matters to allow judgments to be entered in state court with enforcement left to the bankruptcy court, (9) the burden of [the bankruptcy court's] docket, (10) the likelihood that the commencement of the proceeding in bankruptcy court involves forum shopping by one of the parties, (11) the existence of a right to a jury trial, and (12) the presence in the proceeding of nondebtor parties. Christensen v. Tucson Estates (In re Tucson Estates), 912 F.2d 1162, 1167 (9th Cir. 1990).