private void VerifySaveCustomerToRepository(RegisterCustomerUseCase useCase, Customer customer)
        {
            var repository = (MockCustomerRepository)useCase.Repository;

            repository.WasSaveCustomerCalled.Should().BeTrue();
            repository.PassedInCustomer.Should().BeEquivalentTo(customer);
        }
        private void VerifyCallRepositoryGetCustomerByEmailAddress(RegisterCustomerUseCase useCase,
                                                                   CustomerRegistration registration)
        {
            var repository = (MockCustomerRepository)useCase.Repository;

            repository.WasGetCustomerCalled.Should().BeTrue();
            repository.PassedInEmailAddress.Should().Be(registration.EmailAddress);
        }