{"ast_node_type":"other","tokens":[{"end":65,"kind":"keyword","start":0,"text":"ty::FnDef(def_id,"}]}
            ty::FnDef(def_id, ..) => match tcx.def_kind(def_id) {
            ty::Foreign(def_id) => format!("extern type `{}`", tcx.def_path_str(def_id)).into(),
                DefKind::Ctor(CtorOf::Struct, _) => "struct constructor".into(),