code: public function syslog($message, $severity = \TYPO3\CMS\Core\Messaging\FlashMessage::OK)
      {
          switch ($severity) {
              case \TYPO3\CMS\Core\Messaging\FlashMessage::NOTICE:
                  $severity = GeneralUtility::SYSLOG_SEVERITY_NOTICE;
                  break;
              case \TYPO3\CMS\Core\Messaging\FlashMessage::INFO:
                  $severity = GeneralUtility::SYSLOG_SEVERITY_INFO;
                  break;
              case \TYPO3\CMS\Core\Messaging\FlashMessage::OK:
                  $severity = GeneralUtility::SYSLOG_SEVERITY_INFO;
                  break;
              case \TYPO3\CMS\Core\Messaging\FlashMessage::WARNING:
                  $severity = GeneralUtility::SYSLOG_SEVERITY_WARNING;
                  break;
              case \TYPO3\CMS\Core\Messaging\FlashMessage::ERROR:
                  $severity = GeneralUtility::SYSLOG_SEVERITY_ERROR;
                  break;
          }
  
          GeneralUtility::sysLog($message, 'image_autoresize', $severity);
      }
docs: Creates an entry in syslog.
  
  @param string $message
  @param integer $severity
  @return void