Unhandled Exception: Bad state: Future already completed

below code works in android. but doesnt work in iOs

`+0200 Runner[326:18470] [VERBOSE-2:ui_dart_state.cc(199)] Unhandled Exception: Bad state: Future already completed
#0 _AsyncCompleter.complete (dart:async/future_impl.dart:45:31)
#1 VideoPlayerController.initialize (package:video_player/video_player.dart:310:25)
2 ChewieController._initialize (package:chewie/src/chewie_player.dart:395:7)`

`
'class _VideoPlayerScreenState extends State {
final Attachment attachment;

_VideoPlayerScreenState(this.attachment);

VideoPlayerController _controller;
ChewieController chewieController;
Future futureController;

@override
void initState() {
_controller = Service().getAttachmentVideo(attachment.id);

futureController = _controller.initialize();

chewieController = ChewieController(
videoPlayerController: _controller,
autoPlay: true,
looping: false,
showControlsOnInitialize: false);
super.initState();
}

@override
void dispose() {
// Ensure disposing of the VideoPlayerController to free up resources.
chewieController.dispose();
_controller.dispose();

super.dispose();
}

@override
Widget build(BuildContext context) {
return Scaffold(
body: FutureBuilder(
future: futureController,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {

// If the VideoPlayerController has finished initialization, use
// the data it provides to limit the aspect ratio of the video.
final Size size = _controller.value.size;
return Chewie(
controller: chewieController,
);
} else {
// If the VideoPlayerController is still initializing, show a
// loading spinner.
return Center(child: CircularProgressIndicator());
}
},
),
);
}
}`

Start by reproducing the iOS failure from the supplied _VideoPlayerScreenState example, then read VideoPlayerController.initialize and ChewieController._initialize at the stack-trace locations. Compare the initialization flow with Android and determine whether it completes the same Future more than once. Done means the iOS example no longer reports “Future already completed” while video playback still initializes.

Written by the indexing model from the issue text.