public void ReturnFalseAndUnmatchMessage_WhenArgumentIsNotNull()
{
// Arrange.
int? value = 5;
// Act.
IValidationPredicateResult result = NullableNullValidationPredicate<int>.Instance.Match(value);
// Assert.
Assert.IsFalse(result.IsMatch);
Assert.AreEqual("Argument value <5> is not null.", result.Message);
}