public function addIdentifier(string $identifier)
    {
        $count = $this->queueRepository->countOpenByIdentifier($identifier);
        if ($count > 0) {
            return;
        }

        $this->logger->debug('SFC Queue add', [$identifier]);

        $data = [
            'cache_url' => $identifier,
            'page_uid' => 0,
            'invalid_date' => \time(),
            'call_result' => '',
        ];

        $this->queueRepository->insert($data);
    }