{"ast_node_type":"other","tokens":[{"end":33,"kind":"keyword","start":0,"text":")"}]}
    ) -> Option<Instance<'tcx>> {
        rcvr_args: ty::GenericArgsRef<'tcx>,
        let ty::Coroutine(coroutine_def_id, args) = *rcvr_args.type_at(0).kind() else {