Cannot invoke 'logInGuestWithCompletion' with an argument list of type '((TWTRGuestSession!, NSError!) -> _)'

[maxungz]

Hello there im trying to setup Fabric but when i paste the shown code Xcode always shows the error: Cannot invoke ‘logInGuestWithCompletion’ with an argument list of type ‘((TWTRGuestSession!, NSError!) -> _)’

Im using Xcode 6 ( Xcode 7 didn’t find the framework ) and i don’t know what to do.

Thats the code im talking about:

Twitter.sharedInstance().logInGuestWithCompletion { (session: TWTRGuestSession!, error: NSError!) in
        Twitter.sharedInstance().APIClient.loadTweetWithID("20") { (tweet: TWTRTweet!, error: NSError!) in
            self.view.addSubview(TWTRTweetView(tweet: tweet))
        }
    }

[niall]