public void AddLessThanValidationPredicate_WhenArgumentIsLong()
{
// Arrange.
ValidatableArgument<long> argument = new ValidatableArgument<long>("argument", 3);
// Act.
argument.IsLessThan(5);
// Assert.
Assert.AreEqual(1, argument.ValidationPredicates.Count());
Assert.IsInstanceOfType(argument.ValidationPredicates.First(), typeof(LessThanValidationPredicate<long>));
}