@Override
    public boolean addAll(Collection<? extends E> c) {
        for (E e : c) {
            add(e);
        }
        return true;
    }
@Test
    public void testAddAll() {
        queue.addAll(asList(23, 42));

        assertEquals(2, queue.size());
        assertContains(queue, 23);
        assertContains(queue, 42);
    }