我必须使用Kafka模块的代码：https://github.com/akka/reactive-kafka/blob/master/readme.md
我的代码以：

val kafka = new ReactiveKafka()

val kafkaIdpsMsgs: Publisher[StringKafkaMessage] = kafka.consume(
      ConsumerProperties(
        brokerList = kafkaHosts,
        zooKeeperHost = zkHosts,
        topic = "test",
        groupId = "idps-translator",
        decoder = new StringDecoder()
      ).readFromEndOfStream())

    val kafkaSamples: Subscriber[String] = kafka.publish(ProducerProperties(
      brokerList = kafkaHosts,
      topic = "test",
      encoder = new StringEncoder()
    ))

我想（由出版商）发一条消息。我要写什么代码才能实现它？