 import AVFoundation
 import AVKit
 import WWDCAppKit
+import KVOController
 
 private let _nibName = "VideoWindowController"
 

        }
        playerView.player = player
        
        player?.currentItem?.asset.loadValuesAsynchronously(forKeys: ["tracks"]) { [weak self] in
            DispatchQueue.main.async {
                self?.setupWindowSizing()
                self?.setupTimeObserver()
                
                if let session = self?.session {

    // resizes the window so the video fills the entire screen without cropping
    @IBAction func sizeWindowToFill(_ sender: AnyObject?)
    {
        guard aspectRatioSet else { return }
        
        Preferences.SharedPreferences().lastVideoWindowScale = 100.0
        
