{"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"TyKind::CoroutineWitness(coroutine_b,"}]}
                TyKind::CoroutineWitness(coroutine_b, sub_b),
                TyKind::CoroutineWitness(coroutine_a, sub_a),
            ) if coroutine_a == coroutine_b => zip_substs(self, None, sub_a, sub_b)?,