@Override
  public void deregisterChildren(ConfigurationManager manager) {
    if (worker != null) {
      manager.deregisterObserver(worker);
    }
  }
This class encapsulates the details of the {@link RegionNormalizer} subsystem.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/RegionNormalizerManager.java