public async Task GetByIdAsyncWhenInvalidIdReturnsSubscriptionNotFoundResponse()
        {
            // Arrange
            var mockSubscriptionRepository = GetDefaultISubscriptionRepositoryInstance();
            var subscriptionId             = 1;

            mockSubscriptionRepository.Setup(r => r.FindById(subscriptionId))
            .Returns(Task.FromResult <Subscription>(null));
            var mockUnitOfWork = GetDefaultIUnitOfWorkInstance();
            var service        = new SubscriptionService(mockSubscriptionRepository.Object, mockUnitOfWork.Object);
            // Act
            SubscriptionResponse result = await service.GetByIdAsync(subscriptionId);

            var message = result.Message;

            // Assert
            message.Should().Be("Subscription not found");
        }
        public async void ThenTheSystemWillDisplayTheDetailOfThatSubscription()
        {
            var response = await subscriptionService.GetByIdAsync(subscription.Id);

            response.Should().Be(subscription);
        }