@Test public void allows() { Animal a = new Animal(); Cat c = new Cat(); Dog d = new Dog(); PersianCat pc = new PersianCat(); PetCage cage = new PetCage(); assertTrue(cage.allows(a)); assertTrue(cage.allows(c)); assertTrue(cage.allows(d)); assertTrue(cage.allows(pc)); PetCage catCage = new CatCage(); assertTrue(catCage.allows(c)); assertTrue(catCage.allows(pc)); assertFalse(catCage.allows(a)); assertFalse(catCage.allows(d)); }