private <T> KafkaFuture<T> findAndApply(String transactionalId, KafkaFuture.BaseFunction<ProducerIdAndEpoch, T> followup) {
        CoordinatorKey key = CoordinatorKey.byTransactionalId(transactionalId);
        KafkaFuture<ProducerIdAndEpoch> future = futures.get(key);
        if (future == null) {
            throw new IllegalArgumentException("TransactionalId " +
                "`" + transactionalId + "` was not included in the request");
        }
        return future.thenApply(followup);
    }
Return a future which succeeds only if all the producer fencings succeed.
clients/src/main/java/org/apache/kafka/clients/admin/FenceProducersResult.java