{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"(0..fields_len).map(|idx|"}]}
        (0..fields_len).map(|idx| LocalFieldId::from_raw(idx.into())).map(move |fid| {
            let ty = field_tys[fid].clone().substitute(Interner, substs);