$objectManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Object\\ObjectManager');
$configurationManager = $objectManager->get('TYPO3\\CMS\\Extbase\\Configuration\\ConfigurationManagerInterface');
$objectManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Object\\ObjectManager');
$configurationManager = $objectManager->get('TYPO3\\CMS\\Extbase\\Configuration\\ConfigurationManagerInterface');