@Override
 public void dispose() {
   // Set the context menu to null to prevent the editor context menu
   // from being disposed along with the source viewer
   if (fDescriptionViewer != null) {
     fDescriptionViewer.unsetMenu();
     fDescriptionViewer = null;
   }
   super.dispose();
 }
 @Override
 public void dispose() {
   IPluginModelBase model = (IPluginModelBase) getPage().getModel();
   if (model != null) model.removeModelChangedListener(this);
   super.dispose();
 }