package example1; class testingMyStack { private static String moduleName = "COMP213"; public static void main(String[] args) { MyStack.push("COMP101"); MyStack.push(moduleName); String s = MyStack.pop(); System.out.println("popped:" + s); MyStack.push("COMP109"); s = MyStack.pop(); System.out.println("popped:" + s); s = MyStack.pop(); System.out.println("popped:" + s); // The stack should be empty now s = MyStack.pop(); } }