//Visar alla böcker som finns att köpa
        public static void SelectBooksAndShops()
        {
            var bookRepo = new BooksRepository();
            var books    = bookRepo.BookInShop();

            foreach (var book in books)
            {
                if (0 < book.Shops.Count)
                {
                    Console.WriteLine(book.Title + " " + book.ReleaseDate);
                    foreach (var author in book.Authors)
                    {
                        Console.WriteLine(author.Author.FirstName + " " + author.Author.LastName);
                    }
                    foreach (var shop in book.Shops)
                    {
                        Console.WriteLine(shop.Shop.Name);
                    }
                }
            }
        }