@Override
 public void deactivate() {
   if (!isActive()) return;
   BuildStatus.updateDiagramItemMap(
       getViewer().getEditDomain().getCommandStack().toString(), getAllChildren());
   getViewer()
       .getEditDomain()
       .getCommandStack()
       .removeCommandStackEventListener(stackEventListener);
   super.deactivate();
   ((DiagramModel) getModel()).removePropertyChangeListener(this);
 }