如何通过Google登录登录令牌？

Question

在我的应用程序中。我想使用Google帐户登录任何与我的应用同步他的日历。当我使用谷歌SDK登录时，我会看到像Image下面的某种令牌。但我不知道该怎么做。

我使用以下代码登录。

@IBAction func btnGoogleClicked(){

    self.presentViewController(self.createAuthController(), animated: true) { 
        self.hideAddAccountView();
    }
}


//MARK: -  Google calendar Method 

func createAuthController() -> GTMOAuth2ViewControllerTouch{
    let authController : GTMOAuth2ViewControllerTouch;
    let arrScopes = NSMutableArray();

    arrScopes.addObject(kGTLAuthScopeCalendarReadonly)
    arrScopes.addObject("profile")

    authController = GTMOAuth2ViewControllerTouch(scope: arrScopes.componentsJoinedByString(" "), clientID: kClientID, clientSecret: nil, keychainItemName: kKeychainItemName, delegate: self, finishedSelector: #selector(HomeVC.viewController(_:auth:error:)))
    authController.signIn.shouldFetchGoogleUserProfile = true
    return authController;
}

func viewController(vc : GTMOAuth2ViewControllerTouch, auth : GTMOAuth2Authentication,error : NSError?){

    if (error != nil) {
        AlertView.showOKTitleMessageAlert("Authentication Error", strMessage: error!.localizedDescription, viewcontroller: self)
        self.service.authorizer = nil;
    }
    else {

        self.service.authorizer = auth;

        print("email  - \(auth.userEmail)")
        print("userDate  - \(auth.userData)")
        print("properties = \(auth.properties)")
        print("properties = \(vc.signIn.userProfile)")
        print("properties = \(vc.signIn.userData)")
        currentLoginDictionary = vc.signIn.userProfile

        self.dismissViewControllerAnimated(true, completion: nil)
        fatchEvents()

    }
}


func fatchEvents(){

    let query = GTLQueryCalendar.queryForEventsListWithCalendarId("primary")

    query.maxResults = 150;
    query.timeMin = GTLDateTime.init(date: NSDate(), timeZone: NSTimeZone.localTimeZone())
    query.singleEvents = true;
    query.orderBy = kGTLCalendarOrderByStartTime;

    self.service.executeQuery(query, delegate: self, didFinishSelector: #selector(HomeVC.eventFatchedSuccessfully(_:events:error:)))

}

func eventFatchedSuccessfully(ticket : GTLServiceTicket,events : GTLCalendarEvents,error : NSError?){

    print("ticket \(ticket.userData) \(ticket.APIKey)")
}

任何人都可以帮助我。