@Override
 public void setContentEntryEditor(ContentEntryEditor newEditor) {
   PyContentEntriesEditor.MyContentEntryEditor existingEditor = getContentEntryEditor();
   if (Comparing.equal(existingEditor, newEditor)) {
     return;
   }
   if (existingEditor != null) {
     existingEditor.removeListener(myListener);
   }
   if (newEditor != null) {
     ((PyContentEntriesEditor.MyContentEntryEditor) newEditor).addListener(myListener);
   }
   super.setContentEntryEditor(newEditor);
 }