Page Renderer

$this->pageRenderer = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Page\\PageRenderer');
$this->pageRenderer->addCssFile('/typo3conf/ext/extension/Resources/Public/Css/jquery.datatables.css');
$this->pageRenderer->addJsFile('/typo3conf/ext/extension/Resources/Public/Javascript/jquery.datatables.js', 'text/javascript', true, false);