public class Test {
    public static void main(String[] args) {
        BankCallCenter bankCallCenter = new BankCallCenter();
        Client client = new Client("1");
        bankCallCenter.registerObserver(client);
        Client client2 = new Client("2");
        bankCallCenter.registerObserver(client2);
        Client client3 
 
= new Client("3");
        bankCallCenter.registerObserver(client3);
        System.out.println("----------中心叫一號去辦理業務------------");
        bankCallCenter.notifyObserver("1");
        System.out.println("----------從觀察者列表中移除一號------------");
        bankCallCenter.removeObserver(client);
        System.out.println(
 
"-----------中心叫二號去辦理業務-------------");
        bankCallCenter.notifyObserver("2");
        System.out.println("------------從觀察者列表中移除二號-----------");

    }