code: function() {
      var client = this;
      var cconf = this.config.client;
  
      return router(function(app) {
        app.get(cconf.process_login_url, client.auth_process_login.bind(client));
        app.get(cconf.login_url, client.login.bind(client));
        app.get(cconf.logout_url, client.logout.bind(client));
      });
    }
docs: Returns OAuth2 client connect middleware.
  
  This middleware will intercep requests aiming at OAuth2 client
  and treat them.