public function getHttpPushHeaders(string $content): array
    {
        $headers = [];
        /** @var ConfigurationService $configurationService */
        $configurationService = GeneralUtility::makeInstance(ConfigurationService::class);
        if ($configurationService->isBool('sendHttp2PushEnable')) {
            $limit = (int)$configurationService->get('sendHttp2PushFileLimit');
            $extensions = GeneralUtility::trimExplode(',', (string)$configurationService->get('sendHttp2PushFileExtensions'), true);
            $handlers = $this->getHttpPushHandler();

            foreach ($extensions as $extension) {
                foreach ($handlers as $handler) {
                    /** @var AbstractHttpPush $handler */
                    if ($handler->canHandleExtension($extension)) {
                        $headers = \array_merge($headers, $handler->getHeaders($content));
                    }
                }
            }

            $headers = \array_slice($headers, 0, $limit);
        }

        return $headers;
    }