docs: public static void unsetCurrentPersistenceBroker(PBKey key, PersistenceBrokerInternal broker)
              throws PBFactoryException
      {
          HashMap map = (HashMap) currentBrokerMap.get();
          WeakHashMap set = null;
          if(map != null)
          {
              set = (WeakHashMap) map.get(key);
              if(set != null)
              {
                  set.remove(broker);
                  if(set.isEmpty())
                  {
                      map.remove(key);
                  }
              }
              if(map.isEmpty())
              {
                  currentBrokerMap.set(null);
                  synchronized(lock) {
                      loadedHMs.remove(map);
                  }
              }
          }
      }