public void ReturnTrueAndMatchMessage_WhenArgumentIsGuidEmpty()
{
// Arrange.
Guid value = Guid.Empty;
// Act.
IValidationPredicateResult result = GuidEmptyValidationPredicate.Instance.Match(value);
// Assert.
Assert.IsTrue(result.IsMatch);
Assert.AreEqual("The argument is Guid.Empty.", result.Message);
}