@Override
    public void unregister(RaftClient.Listener<ApiMessageAndVersion> listener) {
        eventQueue.append(() -> {
            if (shutdown) {
                log.info("Node {}: can't unregister because local log manager is shutdown", nodeId);
            } else {
                int id = System.identityHashCode(listener);
                if (listeners.remove(listener) == null) {
                    log.error("Node {}: can't unregister because the listener {} doesn't exists", nodeId, id);
                } else {
                    log.info("Node {}: unregistered MetaLogListener {}", nodeId, id);
                }
            }
        });
    }
Shutdown the log manager.

Even though the API suggests a non-blocking shutdown, this method always returns a completed
future. This means that shutdown is a blocking operation.
metadata/src/test/java/org/apache/kafka/metalog/LocalLogManager.java