// can be overwritten
 protected JMenuItem buildJMenuItem(XObject xobject, int valueType) {
   if (valueType == COMPATIBLE_VALUE) {
     return new JMenuItem(xobject.getText());
   } else if (valueType == CURRENT_VALUE) {
     return new JMenuItem("> " + xobject.getText());
   } else if (valueType == NULL_VALUE) {
     return new JMenuItem("null");
   } else {
     return null;
   }
 }