     }
 
     open var isFullscreen: Bool {
-        guard let core = self.core else {
+        guard let core = core else {
             return false
         }
 

        }
    }

    fileprivate func bindPlayer(playback: Playback?) {
        if let avFoundationPlayback = (playback as? AVFoundationPlayback), let player = avFoundationPlayback.player {
            viewController?.player = player
            viewController?.delegate = avFoundationPlayback
        }
    }

    fileprivate func unbindPlaybackEvents() {
        for eventId in playbackEventsListenIds {
            baseObject.stopListening(eventId)
        }

        return baseObject.listenTo(contextObject, eventName: eventName, callback: callback)
    }

    private func bindPlaybackEvents() {
        if let playback = core?.activePlayback {
            for event in playbackEventsToListen {
                let listenId = baseObject.listenTo(
