public static void main(String[] args) {
        FixedCapacityStackOfStrings stackOfStrings = new FixedCapacityStackOfStrings(3);
        stackOfStrings.push("zhu");
        stackOfStrings.push("zhen");
        stackOfStrings.push("guang");

        StdOut.println(stackOfStrings.size());
        while (!stackOfStrings.isEmpty())
            StdOut.println(stackOfStrings.pop());
        StdOut.println(stackOfStrings.size());
        StdOut.println(stackOfStrings.pop());
    }