public static function getThumbnailGeneratorClassNames($objectManager)
    {
        /** @var ReflectionService $reflectionService */
        $reflectionService = $objectManager->get(ReflectionService::class);
        $generatorClassNames = $reflectionService->getAllImplementationClassNamesForInterface(ThumbnailGeneratorInterface::class);
        $configurationManager = $objectManager->get(ConfigurationManager::class);
        $generatorOptions = $configurationManager->getConfiguration('Settings', 'Neos.Media.thumbnailGenerators');
        $generators = [];
        foreach ($generatorClassNames as $generatorClassName) {
            if (isset($generatorOptions[$generatorClassName]['disable']) && $generatorOptions[$generatorClassName]['disable'] === true) {
                continue;
            }
            if (isset($generatorOptions[$generatorClassName]['priority'])) {
                $priority = $generatorOptions[$generatorClassName]['priority'];
            } else {
                $priority = $generatorClassName::getPriority();
            }
            $generators[] = [
                'priority' => (integer)$priority,
                'className' => $generatorClassName
            ];
        }

        $sorter = new PositionalArraySorter($generators, 'priority');
        return array_reverse($sorter->toArray());
    }