{"ast_node_type":"variable","tokens":[{"end":68,"kind":"keyword","start":0,"text":"let"}]}
        let output = tcx.fn_sig(item_def_id).skip_binder().output();
        // an RPITIT (return-position impl trait in trait) or AFIT (async fn in trait).
        let output = if let ty::Alias(ty::Projection, alias_ty) = *output.skip_binder().kind()