private void refreshUserAuthsCache(byte[] data) {
    try {
      this.labelsCache.refreshUserAuthsCache(data);
    } catch (IOException ioe) {
      LOG.error("Failed parsing data from labels table " + " from zk", ioe);
    }
  }
A zk watcher that watches the labels table znode. This would create a znode
/hbase/visibility_labels and will have a serialized form of a set of labels in the system.
hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/ZKVisibilityLabelWatcher.java