{"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"smallvec![(def_id,"}]}
            smallvec![(def_id, smallvec![])];
        let mut stack: SmallVec<[(DefId, SmallVec<[ty::BoundVariableKind; 8]>); 8]> =
        let mut visited: FxHashSet<DefId> = FxHashSet::default();