public static void main(String[] args) {
        Queue<String> queue = new Queue<String>(3);
        queue.enqueue("zhu");
        queue.enqueue("zhen");
        queue.enqueue("guang");

        for (String q : queue) {
            System.out.println(q);
        }

        System.out.println(queue.size());

        queue.dequeue(1);

        for (String s : queue) {
            System.out.println(s);
        }
        System.out.println(queue.size());

        Iterator iterator = queue.iterator();
        while (iterator.hasNext()) {
            iterator.remove();
        }

        System.out.println(queue.size());
    }