public void with_origin_unchanged()
        {
            var origin = new SimpleEventSourcedRoot();

            origin.SetName("Jimi Hendrix");
            var updated = origin.SetName("Jimi Hendrix").Should().BeValid().Value;

            origin.Name.Should().BeNull();
            updated.Name.Should().Be("Jimi Hendrix");
        }
        public void as_uncommitted_to_the_buffer()
        {
            var origin  = new SimpleEventSourcedRoot();
            var updated = origin.SetName("Jimi Hendrix").Should().BeValid().Value;

            updated.Buffer.Uncommitted.Should().ContainSingle();
        }
        public void changes_for_single_event()
        {
            var origin  = new SimpleEventSourcedRoot();
            var updated = origin.SetName("Jimi Hendrix").Should().BeValid().Value;

            updated.Name.Should().Be("Jimi Hendrix");
            updated.Buffer.Uncommitted.Should().BeEquivalentTo(new[] { new NameUpdated {
                                                                           Name = "Jimi Hendrix"
                                                                       } });
        }