{"ast_node_type":"variable","tokens":[{"end":64,"kind":"keyword","start":0,"text":"let"}]}
            let trait_ref = tcx.impl_trait_ref(def_id).unwrap();
        if let DefKind::Impl { of_trait: true } = tcx.def_kind(def_id) {
            let trait_ref = trait_ref.instantiate_identity();