      - Parameter object: object to store
      - Parameter key: key of the value to retrive
      */
-    private func writeObject(object: Any, forKey key: String) {
+    private func writeObject(object: Any?, forKey key: String) {
         let iCloudStore = NSUbiquitousKeyValueStore.default()
         iCloudStore.set(object, forKey: key)
         iCloudStore.synchronize()

            state = .dataAvailable
            delegate?.didUpdateState(manager: self)
        }
    }

    private func configureChangeNotification() {

    public weak var delegate: OSiCloudDataBackupDelegate?

    /// Initialization. Delegate is mandatory.
    public init(delegate: OSiCloudDataBackupDelegate?) {
        self.delegate = delegate
    }

