{"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
        let mut stack: SmallVec<[(DefId, SmallVec<[ty::BoundVariableKind; 8]>); 8]> =
        use smallvec::{SmallVec, smallvec};
            smallvec![(def_id, smallvec![])];