@Override
 protected boolean showPage(IPreferenceNode node) {
   final boolean success = super.showPage(node);
   if (success) {
     history.addHistoryEntry(new PreferenceHistoryEntry(node.getId(), node.getLabelText(), null));
   }
   return success;
 }
 public String getLabel() {
   if (prefix != null && prefix.length() > 0) {
     return preferenceNode.getLabelText() + separator + prefix;
   }
   return preferenceNode.getLabelText();
 }