@Test
 public void testBottomObjectPropertyNegative() {
   OWLObjectPropertyExpression prop = ObjectProperty(getIRI("prop"));
   assertFalse(prop.isOWLBottomObjectProperty());
 }
 @Test
 public void testBottomObjectPropertyPositive() {
   OWLObjectPropertyExpression prop = Factory.getFactory().getOWLBottomObjectProperty();
   assertTrue(prop.isOWLBottomObjectProperty());
 }