public Task <IEnumerable <IBook> > GetBooksAsync(string searchString)
        {
            var datahandler = new Handlers.Datahandler();

            return(datahandler.GetBooksAsync(searchString));
        }
        public Task <IEnumerable <IBook> > PlaceOrderAsync(ICart cart)
        {
            var datahandler = new Handlers.Datahandler();

            return(datahandler.PlaceOrderAsync(cart));
        }