public void ReturnTrueAndMatchMessage_WhenArgumentIsEmpty()
{
// Arrange.
IValidationPredicate<string> validationPredicate = new StringNotRegexMatchValidationPredicate("abc");
string value = string.Empty;
// Act.
IValidationPredicateResult result = validationPredicate.Match(value);
// Assert.
Assert.IsTrue(result.IsMatch);
Assert.AreEqual("Argument value <> does not contain a match of the regular expression <abc>.", result.Message);
}