save function
Implementation
Future<void> save(SaveData saveData, String savePath) async {
final savePath_ =
'${(await getApplicationDocumentsDirectory()).path}${savePath}save_${DateTime.now().millisecondsSinceEpoch}.json';
final saveFile = await File(savePath_).create(recursive: true);
final data = {
'scene_id': saveData.sceneId,
'description': saveData.description,
'state': saveData.state
};
await saveFile.writeAsString(jsonEncode(data));
}