public async Task ReturnsResults()
            {
                var books = await BooksClient.Search("stormlight");

                Assert.NotNull(books);
                Assert.NotEmpty(books.List);
                Assert.True(books.Pagination.TotalItems > 0);
            }
            public async Task ReturnsASecondPage()
            {
                var books = await BooksClient.Search("stormlight", page : 2);

                Assert.NotNull(books);
                Assert.NotEmpty(books.List);
                Assert.True(books.Pagination.TotalItems > 0);
                Assert.True(books.Pagination.Start == 21);
            }