protected function createExtensionSelector()
    {
        $this->getAndSaveSelectedTestableKey();

        /** @var \Tx_Phpunit_ViewHelpers_ExtensionSelectorViewHelper $extensionSelectorViewHelper */
        $extensionSelectorViewHelper =
            GeneralUtility::makeInstance(\Tx_Phpunit_ViewHelpers_ExtensionSelectorViewHelper::class);
        $extensionSelectorViewHelper->injectOutputService($this->outputService);
        $extensionSelectorViewHelper->injectUserSettingService($this->userSettingsService);
        $extensionSelectorViewHelper->injectTestFinder($this->testFinder);
        $extensionSelectorViewHelper->setAction(BackendUtility::getModuleUrl('tools_txphpunitbeM1'));

        $extensionSelectorViewHelper->render();
    }