public class Test {

    public static void main(String[] args) {
        Employer pm = new ProjectManager("專案經理");
        Employer pa = new ProjectAssistant("專案助理");
        Employer programmer1 = new Programmer("程式設計師一");
        Employer programmer2 = new Programmer("程式設計師二");
        
        pm.add(pa);//為專案經理新增專案助理
        pm.add(programmer2);//為專案經理新增程式設計師
        
        List ems = pm.getEmployers();
        for (Employer em : ems) {
            System.out.println(em.getName());
        }
    }
}