function __construct($db = null)
 {
     $this->db = isset($db) ? $db : DTSettingsStorage::defaultStore();
 }
 function __construct($auth_url = null, $db = null)
 {
     $this->db = isset($db) ? $db : DTSettingsStorage::defaultStore();
     $this->auth_url = isset($auth_url) ? $auth_url : "login.php";
 }