function prepare()
 {
     // ----- EXTENSION POINT
     $dashboard_notifications = array();
     $dashboard_notifications = rex_register_extension_point('DASHBOARD_NOTIFICATION', $dashboard_notifications);
     $content = '';
     if (count($dashboard_notifications) > 0) {
         foreach ($dashboard_notifications as $notification) {
             if (rex_dashboard_notification::isValid($notification) && $notification->checkPermission()) {
                 $content .= $notification->_get();
             }
         }
         unset($dashboard_notifications);
     }
     $this->setContent($content);
 }
 function rex_version_checker_notification()
 {
     // default cache lifetime in seconds
     $cache_options['lifetime'] = 3600;
     parent::rex_dashboard_notification('version-checker', $cache_options);
 }