static void Main(string[] args)
{
ApplyForLeaveRequest halfDay = new ApplyForLeaveRequest("Yang-Onion", 0.5D);
ApplyForLeaveRequest twoDays = new ApplyForLeaveRequest("Yang@Onion", 2D);
ApplyForLeaveRequest sevenDays = new ApplyForLeaveRequest("*****@*****.**", 7D);
TeamLeader teamLeader = new TeamLeader("赵云");
ProjectManager projectManager = new ProjectManager("诸葛亮");
Manager manager = new Manager("刘备");
teamLeader.NexApprover = projectManager;
projectManager.NexApprover = manager;
teamLeader.Process(halfDay);
teamLeader.Process(twoDays);
teamLeader.Process(sevenDays);
Console.Read();
}