{
    EFactory oldEFactoryInstance = eFactoryInstance;
    eFactoryInstance = newEFactoryInstance;
    if (eNotificationRequired())
    {
      ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, EcorePackage.EPACKAGE__EFACTORY_INSTANCE, oldEFactoryInstance, newEFactoryInstance);
      if (msgs == null) msgs = notification; else msgs.add(notification);
    }
    return msgs;
  }