public void stop() {
        boolean wasShuttingDown = shutdown.getAndSet(true);
        if (!wasShuttingDown) {
            log.info("Kafka MirrorMaker stopping");
            if (internalServer != null) {
                Utils.closeQuietly(internalServer::stop, "Internal REST server");
            }
            for (Herder herder : herders.values()) {
                try {
                    herder.stop();
                } finally {
                    stopLatch.countDown();
                }
            }
            log.info("Kafka MirrorMaker stopped.");
        }
    }
@param config    MM2 configuration from mm2.properties file
@param clusters  target clusters for this node. These must match cluster
                 aliases as defined in the config. If null or empty list,
                 uses all clusters in the config.
@param time      time source
connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorMaker.java