public async Task WillThrowWhenCuratedPackageDoesNotExist()
            {
                var svc = new TestableCuratedFeedService();

                await Assert.ThrowsAsync <InvalidOperationException>(
                    async() => await svc.ModifyCuratedPackageAsync(
                        0,
                        404,
                        false));
            }
            public async Task WillModifyAndSaveTheCuratedPackage()
            {
                var svc = new TestableCuratedFeedService();

                await svc.ModifyCuratedPackageAsync(
                    0,
                    1066,
                    true);

                Assert.True(svc.StubCuratedPackage.Included);
                svc.StubCuratedPackageRepository.Verify(stub => stub.CommitChangesAsync());
            }
            public async Task WillModifyAndSaveTheCuratedPackage()
            {
                var svc = new TestableCuratedFeedService();

                await svc.ModifyCuratedPackageAsync(
                    0,
                    1066,
                    true);

                Assert.True(svc.StubCuratedPackage.Included);
                svc.StubCuratedPackageRepository.Verify(stub => stub.CommitChangesAsync());
            }
            public async Task WillThrowWhenCuratedPackageDoesNotExist()
            {
                var svc = new TestableCuratedFeedService();

                await Assert.ThrowsAsync<InvalidOperationException>(
                    async () => await svc.ModifyCuratedPackageAsync(
                        0,
                        404,
                        false));
            }