public void ReturnFalseAndUnmatchMessage_WhenArgumentIsNull()
{
// Arrange.
string value = null;
// Act.
IValidationPredicateResult result = StringNotNullOrWhiteSpaceValidationPredicate.Instance.Match(value);
// Assert.
Assert.IsFalse(result.IsMatch);
Assert.AreEqual("The argument is null, an empty string or consists only of white space characters.", result.Message);
}