@Override
 protected Collection<? extends EStructuralFeature> getChildrenFeatures(Object object) {
   if (childrenFeatures == null) {
     super.getChildrenFeatures(object);
     childrenFeatures.add(ScaPackage.Literals.SCA_PORT_CONTAINER__PORTS);
   }
   return childrenFeatures;
 }
  @Override
  public void notifyChanged(Notification notification) {
    updateChildren(notification);

    switch (notification.getFeatureID(ScaWaveform.class)) {
      case ScaPackage.SCA_WAVEFORM__PORTS:
        fireNotifyChanged(new ViewerNotification(notification, this, true, false));
        return;
      default:
        break;
    }
    super.notifyChanged(notification);
  }