public function validateAdditionalFields(
        array &$submittedData,
        SchedulerModuleController $schedulerModule
    ) {
        $result = false;

        // validate site
        $sites = $this->siteRepository->getAvailableSites();
        if (array_key_exists($submittedData['site'], $sites)) {
            $result = true;
        }

        // escape limit
        $submittedData['documentsToIndexLimit'] = intval($submittedData['documentsToIndexLimit']);

        return $result;
    }