{"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":"structurally_relate_tys(self,"}]}
        structurally_relate_tys(self, a, b).unwrap();
    fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>> {
        Ok(a)