{"ast_node_type":"variable","tokens":[{"end":73,"kind":"keyword","start":0,"text":"let"}]}
            let ty = field_tys[fid].clone().substitute(Interner, substs);
        (0..fields_len).map(|idx| LocalFieldId::from_raw(idx.into())).map(move |fid| {
            let ty = normalize(self.db, self.db.trait_environment_for_body(self.body), ty);