Classes/Service/ImageResizer.php
protected function getIndexer(\TYPO3\CMS\Core\Resource\ResourceStorage $storage)
    {
        return GeneralUtility::makeInstance(Indexer::class, $storage);
    }
protected function getIndexer(\TYPO3\CMS\Core\Resource\ResourceStorage $storage)
    {
        return GeneralUtility::makeInstance(Indexer::class, $storage);
    }
Gets the indexer

@param ResourceStorage $storage
@return Indexer