{"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"expected_trait:"}]}
        expected_trait: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
        mplace: &MPlaceTy<'tcx, M::Provenance>,
    ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> {