{"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"CoroutineKind::AsyncGen"}]}
            CoroutineKind::AsyncGen { return_impl_trait_id, .. } => {
            CoroutineKind::Gen { return_impl_trait_id, .. } => (return_impl_trait_id, None),
                (return_impl_trait_id, Some(Arc::clone(&self.allow_async_iterator)))