public void CanValidate ()
{
SubclassTypeValidator v = new SubclassTypeValidator (typeof (A));
Assert.IsFalse (v.CanValidate (typeof (string)));
Assert.IsFalse (v.CanValidate (typeof (int)));
Assert.IsFalse (v.CanValidate (typeof (object)));
Assert.IsTrue (v.CanValidate (typeof (Type)));
}