public function isValid()
 {
     if (!parent::isValid()) {
         return false;
     }
     return true;
 }
 public function isValid()
 {
     if (!parent::isValid()) {
         return false;
     }
     $redirect_uri = $this->getRedirectUri();
     if (is_null($redirect_uri)) {
         return false;
     }
     return true;
 }
 public function isValid()
 {
     if (!parent::isValid()) {
         return false;
     }
     $refresh_token = $this->getRefreshToken();
     if (is_null($refresh_token)) {
         return false;
     }
     return true;
 }