public function clearIndexQueueAction()
    {
        $this->indexQueue->deleteItemsBySite($this->selectedSite);
        $this->addFlashMessage(
            LocalizationUtility::translate('solr.backend.index_administration.success.queue_emptied', 'Solr',
                [$this->selectedSite->getLabel()])
        );
        $this->redirectToReferrerModule();
    }