AclControlManager build() {
            if (logContext == null) logContext = new LogContext();
            if (snapshotRegistry == null) snapshotRegistry = new SnapshotRegistry(logContext);
            return new AclControlManager(logContext, snapshotRegistry);
        }
The AclControlManager manages any ACLs that are stored in the __cluster_metadata topic.
If the ACLs are stored externally (such as in ZooKeeper) then there will be nothing for
this manager to do.
metadata/src/main/java/org/apache/kafka/controller/AclControlManager.java