trait_obligation: TraitObligation<'tcx>,
stalled_on: &mut Vec<TyOrConstInferVar<'tcx>>,
) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>> {
trait_obligation: TraitObligation<'tcx>,
stalled_on: &mut Vec<TyOrConstInferVar<'tcx>>,
) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>> {