             if let token = timebaseRangeToken {
                 center.removeObserver(token)
             }
-
+            
             guard let timebase: CMTimebase = newValue() else { return }
             
             weak var this = self

                                     context: nil)
                
                if let new = newItem {
                    center.addObserver(
                        self,
                        selector: #selector(SystemPlayerObserver.didPlayToEnd),

                                  name: kCMTimebaseNotification_EffectiveRateChanged as NSNotification.Name,
                                  object: player.currentItem)
        }
        player.currentItem?.asset.removeObserver(self, forKeyPath: #keyPath(AVAsset.duration))
    }
}
