public function getUrl()
  {
      $url = $this->baseAuthUrl;
      $url .= '?response_type=code';
      $url .= '&client_id='.$this->clientId;
      $url .= '&redirect_uri='.$this->redirectUri;
      $url .= '&scope='.implode(' ', $this->scopes);
      $url .= '&state='.$this->state;

      return $url;
  }