public void CanValidate ()
{
PositiveTimeSpanValidator v = new PositiveTimeSpanValidator ();
Assert.IsTrue (v.CanValidate (typeof (TimeSpan)), "A1");
Assert.IsFalse (v.CanValidate (typeof (int)), "A2");
Assert.IsFalse (v.CanValidate (typeof (long)), "A3");
}