public virtual void ShouldCallAppropriateSpecificationMethod()
        {
            var spec = Substitute.For<ISpecification>();

            var customer = new Customer(SeqGuid.NewGuid(), new FullName("Test", "Test"));
            spec.IsSatisfiedBy(customer).Returns(true);
            customer.Satisfy(spec).Should().Be(true);
            spec.Received(1).IsSatisfiedBy(customer);
        }