 private let PlayerTracksKey = "tracks"
 private let PlayerPlayableKey = "playable"
 private let PlayerDurationKey = "duration"
-private let PlayerRateKey = "rate"
 private let PlayerTimeControlStatusKey = "timeControlStatus"
 
 // KVO player item keys

            }

        } else if context == &PlayerObserverContext {

            // PlayerRateKey
            
            // PlayerTimeControlStatusKey
            

    // MARK: -

    override open func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey: Any]?, context: UnsafeMutableRawPointer?) {

        if context == &PlayerItemObserverContext {

