protected function renderProgressbar()
    {
        /** @var \Tx_Phpunit_ViewHelpers_ProgressBarViewHelper $progressBarViewHelper */
        $progressBarViewHelper = GeneralUtility::makeInstance(\Tx_Phpunit_ViewHelpers_ProgressBarViewHelper::class);
        $progressBarViewHelper->injectOutputService($this->outputService);
        $progressBarViewHelper->render();
    }