/**
  * Initialize the theme list.
  */
 public function init()
 {
     if (!$this->isInitialized) {
         $this->setThemes($this->themeContainer->getThemeList());
         $this->isInitialized = true;
     }
 }
 /**
  * {@inheritdoc}
  */
 public function switchAction(Request $request)
 {
     if ($this->themeContainer instanceof ThemeContainerInterface) {
         $this->themes = $this->themeContainer->getThemeList();
     }
     return parent::switchAction($request);
 }