{"ast_node_type":"variable","tokens":[{"end":96,"kind":"keyword","start":0,"text":"let"}]}
            let kind = ty::LateParamRegionKind::from_bound(ty::BoundVar::from_usize(idx), kind);
        if let ty::BoundVariableKind::Region(kind) = bound_var {
            let liberated_region = ty::Region::new_late_param(tcx, mir_def_id.to_def_id(), kind);