private static void Replay()
        {
            CommandStore = CommandStoreHelper.Load();
            Inventory    = InventoryHelper.LoadFromStore(CommandStore);

            InventoryHelper.Save(Inventory);
            CommandStoreHelper.Save(CommandStore);
        }
        private static void InsertTest()
        {
            CommandStore = CommandStoreHelper.Load();
            Inventory    = InventoryHelper.Load(CommandStore);

            var phone  = new InventoryItem("Blackberry Q10", "mobile phone");
            var phone1 = new InventoryItem("Blackberry Q10", "mobile phone");

            Inventory.AddItem(phone);
            Inventory.AddItem(phone1);

            InventoryHelper.Save(Inventory);
            CommandStoreHelper.Save(CommandStore);
        }