public void ShouldAppendDomainEventToEndOfStream()
            {
                TestAggregateRoot aggregateRoot = new TestAggregateRoot(Guid.NewGuid());

                var stream = new DomainEventStream(aggregateRoot.Id);

                stream.Should().HaveCount(0);

                var aggregateRootDomainEvent = new AggregateRootChangedDomainEvent(aggregateRoot.Id, Guid.NewGuid());
                IDomainEventStream result    = stream.AppendDomainEvent(aggregateRootDomainEvent);

                result.Should().HaveCount(1);
            }