通过登录在Cognito中注册设备

Question

我正在尝试使用AWS Mobile SDK在iOS应用中登录后在Cognito中注册设备。我引用的是AWS博客文章Tracking and Remembering Devices Using Amazon Cognito Your User Pools，但返回的返回值为空，并且该设备在Cognito中不会为用户显示。 AWS博客文章中介绍了我遵循的步骤，如下所示。我还包括了null返回描述。谁能帮助我了解我所缺少的内容或建议其他尝试方法。

// User Sign In Functions
CognitoManager.shared.login(emailId, password: password, callback: { (success: Bool, error: NSError?) -> (Void) in
      if(success)
      {
        let lc = LicenseCheck()
        lc.getLicenseUserInfoAgain(_email: emailId)
        let response = CognitoManager.shared.registerUser?.updateDeviceStatus(true)
        print("response \(response)")
      }
func updateDeviceStatus(_ email : String){
    let user = pool!.getUser(email)
    user.updateDeviceStatus(true)
    let deviceToken = UserDefaults.standard.value(forKey: LoggedInUser.shared.deviceToken) as! String
    let response = user.updateDeviceStatus(deviceToken, remembered: true)
    response.continueOnSuccessWith { (task :AWSTask<AWSCognitoIdentityUserUpdateDeviceStatusResponse>) -> Any? in
      guard task.error == nil else {
        print("Error")
        return nil
      }
      print("Success")
      return nil
    }
  } 

**// Return Value
response Optional(<AWSTask: 0x127644f50; completed = YES; cancelled = NO; faulted = YES; result = (null)>)**