{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
                let trait_ref = tcx.impl_trait_ref(def_id).unwrap().instantiate_identity();
            hir::ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }) => {
                if trait_ref.has_non_region_param() {