@Override
    public boolean addAll(Collection<? extends E> c) {
        for (E e : c) {
            add(e);
        }
        return true;
    }
@Test(expected = IllegalStateException.class)
    public void testAddAll_whenOverCapacity_thenThrowException() {
        queue.addAll(asList(1, 2, 3, 4, 5, 6));
    }