/**
  * @static
  * @param $fileName
  * @param int $etSID - email template SID
  * @return bool
  */
 public static function openEmailTemplateFile($fileName, $etSID)
 {
     $emailTpl = SJB_EmailTemplateEditor::getEmailTemplateBySID($etSID);
     $file_info = SJB_UploadFileManager::getEmailTemplateFileMimeTypeByFilename($emailTpl->getPropertyValue('file'));
     if ($file_info) {
         $file_link = SJB_UploadFileManager::getUploadedFileLink($file_info['id'], false, true);
         for ($i = 0; $i < ob_get_level(); $i++) {
             ob_end_clean();
         }
         header('Content-Length:' . filesize($file_link));
         header('Content-Disposition: attachment; filename="' . $fileName . '"');
         header('Content-type: ' . $file_info['mime_type']);
         readfile($file_link);
         exit;
     }
     return false;
 }