^ That's for the enumeration, the documentation for MPNowPlayingInfoCenter's playbackState instance property specifies it's only for MacOS under Discussion: "This property only applies to macOS. You must set this property every time the app begins or halts playback, otherwise remote control functionality may not work as expected." https://developer.apple.com/documentation/mediaplayer/mpnowplayinginfocenter/2588243-playbackstate