private void stop(boolean swallowException) {
        log.trace("Stopping the Connect group member.");
        AtomicReference<Throwable> firstException = new AtomicReference<>();
        this.stopped = true;
        Utils.closeQuietly(coordinator, "coordinator", firstException);
        Utils.closeQuietly(metrics, "consumer metrics", firstException);
        Utils.closeQuietly(client, "consumer network client", firstException);
        AppInfoParser.unregisterAppInfo(JMX_PREFIX, clientId, metrics);
        if (firstException.get() != null && !swallowException)
            throw new KafkaException("Failed to stop the Connect group member", firstException.get());
        else
            log.debug("The Connect group member has stopped.");
    }
Get the version of the connect protocol that is currently active in the group of workers.

@return the current connect protocol version
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/WorkerGroupMember.java