   override func viewWillDisappear(animated: Bool) {
     super.viewWillDisappear(animated)
     player?.pause()
+
+    if let playerItem = player?.currentItem {
+      let duration: NSTimeInterval = CMTimeGetSeconds(playerItem.duration)
+      let currentTime: NSTimeInterval = CMTimeGetSeconds(playerItem.currentTime())
+
+      Tracker.track(Event(name: "Played Video", details: [
+        "Duration": currentTime,
+        "Fraction": currentTime / duration
+      ]))
+    }
   }
 
   // MARK: - Trackable

      return
    }

    NSNotificationCenter.defaultCenter().addObserver(
      self,
      selector: #selector(handlePlayerItemDidPlayToEndTime(_:)),
      name: AVPlayerItemDidPlayToEndTimeNotification,
      object: playerItem
    )

    player = AVPlayer(playerItem: playerItem)
    player?.play()
  }

}

  }

  deinit {
    for notification in playerItemNotifications {
      NSNotificationCenter.defaultCenter().removeObserver(self, name: notification, object: nil)
    }
  }

  // MARK: - UIViewController
