     }
     
     func track(progress: Progress, description: String) {
+        trackedProgress = progress
         textLabel.text = description
         
         progressView.setProgress(0, animated: false)

    
    func markComplete() {
        observers = nil
        progressView.setProgress(1, animated: true)
        UIView.animate(withDuration: 0.5, delay: 0.25, options: [.curveEaseIn], animations: {
            self.progressView.alpha = 0.0

        return observers != nil
    }
    
    private var trackedProgress: Progress?
    private var observers: [NSKeyValueObservation]?
    
    override init(frame: CGRect) {
