code: public static void deactivateAllCallbackHandlers() {
  	synchronized(callbackHandlers) {
  	    Enumeration e = callbackHandlers.elements();
  	    while(e.hasMoreElements()) {
  		CallbackHandler handler = (CallbackHandler)e.nextElement();
  		handler.shutdown();
  	    }
  	    callbackHandlers.clear();
  	}
      }
docs: Deactivates all callback handlers.