code: function(tokenObject) {
                  var that = this;
  
                  if (this.driver._refreshHandlerPromise) {
                      return this.driver._refreshHandlerPromise;
                  }
  
                  if (tokenObject.refreshToken) {
                      console.log('corbeljs:services:token:refresh');
                      this.driver._refreshHandlerPromise = this.driver.iam.token().refresh(
                          tokenObject.refreshToken,
                          this.driver.config.get(corbel.Iam.IAM_TOKEN_SCOPES, '')
                      );
  
                  } else {
                      console.log('corbeljs:services:token:create');
                      this.driver._refreshHandlerPromise = this.driver.iam.token().create();
                  }
  
                  return this.driver._refreshHandlerPromise
                      .then(function(response) {
                          that.driver.trigger('token:refresh', response.data);
                          that.driver._refreshHandlerPromise = null;
                          return response;
                      }).catch(function(err) {
                          that.driver._refreshHandlerPromise = null;
                          throw err;
                      });
              }
docs: Default token refresh handler
  Only requested once at the same time
  @return {Promise}