@Test
 public void testTopDataPropertyNegative() {
   OWLDataPropertyExpression prop = DataProperty(getIRI("prop"));
   assertFalse(prop.isOWLTopDataProperty());
 }
 @Test
 public void testTopDataPropertyPositive() {
   OWLDataPropertyExpression prop = Factory.getFactory().getOWLTopDataProperty();
   assertTrue(prop.isOWLTopDataProperty());
 }