自定义控件未显示在MobileVLCKit媒体播放器中

Question

我在swift项目中使用MobileVLCKit。我正在使用cocoapod MobileVLCKit-prod（2.7）。我想为播放器添加视频控件。这是我的代码。

 override func viewDidAppear(_ animated: Bool) {
       super.viewDidAppear(animated)
       let filePath = Bundle.main.url(forResource: "bunny", withExtension: "webm")
       self.mediaPlayer.media = VLCMedia(url: filePath)
       self.mediaPlayer.drawable = self.view
       self.addVideoControls()
       self.mediaPlayer.play()    

}

func addVideoControls() {
    let videoControls = MPVolumeView(frame: CGRect(x: 0, y: 0, width: self.view.frame.maxX, height: 60.0))
    videoControls.backgroundColor = UIColor.blue
    let videoView = self.mediaPlayer.drawable as! UIView
    videoView.addSubview(videoControls)
    videoView.bringSubview(toFront: videoControls)
}

VLC团队提供的探索不是编译。如何自定义视频播放器。请理解我的代码中有什么问题。