public void dispose() {
   super.dispose();
   FeatureModelManager mng = PDECore.getDefault().getFeatureModelManager();
   mng.removeFeatureModelListener(this);
   fModel.removeModelChangedListener(this);
   if (fSiteLabelProvider != null) fSiteLabelProvider.dispose();
 }
 /* (non-Javadoc)
  * @see org.eclipse.jface.viewers.LabelProvider#dispose()
  */
 public void dispose() {
   super.dispose();
   PDEPlugin.getDefault().getLabelProvider().disconnect(this);
 }