### Question:
ElementContainer implements Iterable<GraphicsElement> { public void add(InteractiveGraphicsElement element) { interactiveElements.add(element); add((GraphicsElement) element); }  void add(InteractiveGraphicsElement element); void add(GraphicsElement element); Executor onElementAtPoint(Coordinate point); @Override Iterator<GraphicsElement> iterator(); void clear();  }### Answer:
@Test public void iteratesOverInteractiveElements() throws Exception { InteractiveGraphicsElement element = mock(InteractiveGraphicsElement.class); container.add(element); assertThat(Iterables.contains(container, element), is(true)); }
@Test public void iteratesOverInertElements() throws Exception { GraphicsElement element = mock(GraphicsElement.class); container.add(element); assertThat(Iterables.contains(container, element), is(true)); }