yii\bootstrap\Dropdown::run PHP Method

    public function run()
    {
        BootstrapPluginAsset::register($this->getView());
        $this->registerClientEvents();
        return $this->renderItems($this->items, $this->options);
    }

 public function run()
 {
     // Only show this widget if we're not on the error page
     if ($this->_isError) {
         return '';
     } else {
         return parent::run();
     }
 }