@Override
        public void close() {
            producer.close();
        }
Send a message to the topic.

@param key       the key of the message, optional
@param payload   the payload of the message
@param partition the partition to send the message to, optional
@return a future that completes when the message is sent
tools/src/main/java/org/apache/kafka/tools/automq/perf/ProducerService.java