/**
  *
  **/
 public static function verify()
 {
     $req = new OAuthRequestVerifier();
     $result = $req->verifyExtended('access');
     self::$consumer_key = $result['consumer_key'];
     $query = "SELECT user_id FROM oauth_mapping WHERE oauth_id = ?";
     $statement = DBManager::get()->prepare($query);
     $statement->execute(array($result['user_id']));
     $user_id = $statement->fetchColumn();
     if (!$user_id) {
         throw new Exception('Precondition failed', 412);
     }
     return $user_id;
 }