@Override
    public void beginShutdown() {
        eventQueue.beginShutdown("beginShutdown");
    }
Remove a publisher and close it.

@param publisher         The publisher to remove and close.

@return                  A future which yields null when the publisher has been removed
                         and closed, or an exception if the removal failed.
metadata/src/main/java/org/apache/kafka/image/loader/MetadataLoader.java