static function siteForDomain($domain)
 {
     $snt = Status_network_tag::withTag('domain=' . $domain);
     while ($snt->fetch()) {
         $sn = Status_network::staticGet('site_id', $snt->site_id);
         if (!empty($sn)) {
             return $sn;
         }
     }
     return null;
 }