private void switchPerspective(MPerspective perspective) {
   if (perspective.isToBeRendered() && perspective.getWidget() == null)
     engine.createGui(perspective);
   partService.switchPerspective(perspective);
   this.activePerspective = perspective;
   if (perspective.getElementId() != null) {
     String perspectiveId = perspective.getElementId().trim();
     application.getContext().set("activePerspective", perspectiveId);
   }
 }
 @Execute
 public void execute(MApplication app, EPartService partService, EModelService modelService) {
   MPerspective element = (MPerspective) modelService.find(PART_ID, app);
   partService.switchPerspective(element);
 }