{"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"(0..NUM_PREINTERNED_RE_VARS).map(|n|"}]}
            (0..NUM_PREINTERNED_RE_VARS).map(|n| mk(ty::ReVar(ty::RegionVid::from(n)))).collect();
        let re_vars =