public void maximum_item_count() { var pass = Check.That(subject).container[Should.HaveLessThan(4)]; var fail = Check.That(subject).container[Should.HaveLessThan(3)]; Assert.That(pass.Success); Assert.That(fail.Success, Is.False); Assert.That(fail.Reasons, Contains.Item("Outer.container should have less than 3 items")); }