How do we switch video/audio streams? about mediasoup-client-flutter HOT 3 OPEN

    await Helper.switchCamera(
       videoStream!.getVideoTracks()[0],
        videoInputDeviceId,
        videoStream,
    );

final oldTrack = videoStream?.getVideoTracks().first;
await oldTrack!.stop();

// Throws PlatformException(mediaStreamRemoveTrack: Track is nil, null, null, null)
// await videoStream?.removeTrack(oldTrack, removeFromNative: true);

MediaStream newTrackStream = await getDeviceStream(getRootContext());

final newTrack = newTrackStream.getVideoTracks().first;
await videoStream!.addTrack(newTrack, addToNative: true);

videoStream = newTrackStream;

sendProduce(
  stream: newTrackStream,
  codec: codec,
  track: newTrack,
);