@Test
  public void testPerformerAttacksAnimal() {
    World world = new WorldImpl(10, 10, null, null);
    WorldObject performer = TestUtils.createIntelligentWorldObject(2, "performer");

    CreatureGenerator creatureGenerator =
        new CreatureGenerator(TestUtils.createIntelligentWorldObject(1, "cow"));
    int cowId = creatureGenerator.generateCow(0, 0, world);
    WorldObject cow = world.findWorldObjectById(cowId);

    assertEquals(false, cow.getProperty(Constants.ANIMAL_ENEMIES).contains(performer));

    DefaultGoalObstructedHandler.performerAttacksAnimal(performer, cow);

    assertEquals(true, cow.getProperty(Constants.ANIMAL_ENEMIES).contains(performer));
  }