code: private void fireEvent(ManagerEvent event)
      {
          synchronized (eventListeners)
          {
              for (ManagerEventListener listener : eventListeners)
              {
                  try
                  {
                      listener.onManagerEvent(event);
                  }
                  catch (RuntimeException e)
                  {
                      logger.warn("Unexpected exception in eventHandler " + listener.getClass().getName(), e);
                  }
              }
          }
      }
docs: Notifies all {@link ManagerEventListener}s registered by users.
  
  @param event the event to propagate