readJson<T>  static method 
Read a JSON value from the local storage
Implementation
static Future<dynamic> readJson<T>(String key, {dynamic defaultValue}) async {
  String? data = await manager().read(key: key);
  if (data == null) {
    return defaultValue;
  }
  try {
    return jsonDecode(data);
  } on Exception catch (e) {
    NyLogger.error(e.toString());
    return null;
  }
}