iOS - openURL from Custom Keyboard Extension

gistfile1.txt

    func openURL(url: String) {
        var responder: UIResponder = self
        while responder.nextResponder() != nil {
            responder = responder.nextResponder()!
            NSLog("responder = %@", responder)
            if responder.respondsToSelector("openURL:") == true {
                responder.performSelector("openURL:", withObject: NSURL(string: url))
            }
        }
    }