Firebase Cloud Messaging AppDelegate Error : <p>This is code in the Firebase Docs.</p>

<pre><code>if #available(iOS 10.0, *) {
        let authOptions : UNAuthorizationOptions = [.Alert, .Badge, .Sound]
        UNUserNotificationCenter.currentNotificationCenter().requestAuthorizationWithOptions(
            authOptions,
            completionHandler: {_,_ in })

        // For iOS 10 display notification (sent via APNS)
        UNUserNotificationCenter.currentNotificationCenter().delegate = self
        // For iOS 10 data message (sent via FCM)
        FIRMessaging.messaging().remoteMessageDelegate = self

    } else {
        let settings: UIUserNotificationSettings = UIUserNotificationSettings(forTypes: [.Alert, .Badge, .Sound], categories: nil)
        application.registerUserNotificationSettings(settings)
    }
</code></pre>

<p>I didn't modified any line of code. But Xcode says "Use of undeclared type <code>UNAuthorizationOptions</code>, <code>UNUserNotificationCenter</code>, <code>FIRMessagingDelegate</code>"</p>

<p>and I have one more line.</p>

<pre><code>NotificationCenter.defaultCenter.addObserver(self,selector: #selector(self.tokenRefreshNotification),name: kFIRInstanceIDTokenRefreshNotification,object: nil)
</code></pre>

<p>It says "Value of Type AppDelegate has no member <code>tokenRefreshNotification</code>"</p>

<p>I just copied and pasted my code from firebase docs but there is error!</p>
