private Producer getProducer(String topic) {
        return producerInfoMap.computeIfAbsent(topic, (k) -> initTopicProducer(topic));
    }
If this function is called successively without calling {@see #destroyConnection()}, only the
first call has any effect.

@throws FlumeException if an RPC client connection could not be opened
inlong-audit/audit-proxy/src/main/java/org/apache/inlong/audit/sink/pulsar/PulsarClientService.java