Classes/Console/Core/Booting/Scripts.php
private static function registerImplementation($className, $alternativeClassName)
    {
        /** @var $extbaseObjectContainer \TYPO3\CMS\Extbase\Object\Container\Container */
        $extbaseObjectContainer = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Object\Container\Container::class);
        $extbaseObjectContainer->registerImplementation($className, $alternativeClassName);
    }
private static function registerImplementation($className, $alternativeClassName)
    {
        /** @var $extbaseObjectContainer \TYPO3\CMS\Extbase\Object\Container\Container */
        $extbaseObjectContainer = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Object\Container\Container::class);
        $extbaseObjectContainer->registerImplementation($className, $alternativeClassName);
    }
Tell Extbase about this implementation

@param string $className
@param string $alternativeClassName