/*
  * @see IWorkbenchPreferencePage#performDefaults
  */
 public boolean performOk() {
   XMLPlugin plugin = XMLPlugin.getDefault();
   if (!plugin.getIdMaps().equals(fIdMaps)
       || !plugin.getIdExtensionToName().equals(fIdExtensionToName)
       || !plugin.getOrderedElements().equals(fOrderedElements))
     plugin.setIdMaps(fIdMaps, fIdExtensionToName, fOrderedElements, true);
   // XMLPlugin.getDefault().setIdMaps(fIdMaps,fIdExtensionToName,null);
   return super.performOk();
 }