}
@Test
public void test_interactions() {
World w = new World(new PostOffice(), new HCamera());
TestBeing2 b1 = new TestBeing2();
TestBeing2 b2 = new TestBeing2();
w.register(b1, b2, new TestInteractor1());
w.update();
w.update();
assertTrue(b1.interacted);
assertTrue(b2.interacted);
w = new World(new PostOffice(), new HCamera());
b1 = new TestBeing2();
b2 = new TestBeing2();
w.register(b1, b2, new TestInteractor1());
w.update();
w.update();
assertTrue(b1.interacted);
assertTrue(b2.interacted);
w = new World(new PostOffice(), new HCamera());
b1 = new TestBeing2();
b2 = new TestBeing2();
w.register(b1, b2, new TestInteractor2());
w.update();
w.update();