public static function isAllowed()
 {
     global $wgUser;
     $userRights = $wgUser->getEffectiveGroups();
     $allowed = 0;
     foreach ($userRights as $right) {
         if (in_array($right, WikiStats::allowedGroups())) {
             $allowed = 1;
             break;
         }
     }
     return $allowed;
 }