public async Task <IActionResult> AvailableBooks()
        {
            IEnumerable <BookViewModel> booksList;

            try
            {
                booksList = await _rentalsService.GetAvailableBooksCollection();
            }
            catch (Exception e)
            {
                return(BadRequest(e.Message));
            }

            return(Ok(booksList));
        }
        // GET: Rentals/AvailableBooks
        public async Task <IActionResult> AvailableBooks()
        {
            IEnumerable <BookViewModel> booksList;

            try
            {
                booksList = await _rentalsService.GetAvailableBooksCollection();
            }
            catch (Exception e)
            {
                return(BadRequest(e.Message));
            }

            ViewData["Title"] = "Available Books";

            return(View(nameof(Index), booksList));
        }