public static function createInstance(sfWebRequest $request, sfSecurityUser $user)
 {
     $mobile = $request->getMobile();
     $className = 'opOpenSocialLocation';
     if ($mobile->isDoCoMo()) {
         $className .= 'Docomo';
     } elseif ($mobile->isEZweb()) {
         $className .= 'EZweb';
     } elseif ($mobile->isSoftbank() && $mobile->isType3GC()) {
         $className .= 'Softbank';
     } else {
         throw new LogicException("This UserAgent isn't supported.");
     }
     return new $className($request, $user);
 }