     func save() throws {
         var object = [String: Any]()
         object[Const.Key.sNumber] = self.sNumber.value
+        object[Const.Key.unixPassword] = self.unixPassword.value
 
         let data = try JSONSerialization.data(withJSONObject: object, options: .prettyPrinted) // for better readability
         UserDefaults.standard.set(data, forKey: Const.userDefaultsKey)

        // keys
        enum Key {
            static let sNumber = "sNumber"
        }
    }

    private(set) var sNumber = Setting<String>()

    private let disposeBag = DisposeBag()


        switch key {
        case Const.Key.sNumber:
            try self.sNumber.setValue(value)
        case Const.Key.unixPassword:
            try self.unixPassword.setValue(value)
        default:
            throw Err.unknownKey(key)
        }
