{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":")"}]}
    ) -> (Vec<RegionAndOrigin<'tcx>>, FxHashSet<RegionVid>, bool) {
        mut dup_vec: Option<&mut IndexSlice<RegionVid, Option<RegionVid>>>,
        struct WalkState<'tcx> {