1.　设计一个交通信号灯系统：
变量：位置、颜色（红、黄、绿）、显示时间（秒）
方法：切换信号灯
要求：
设计路口信号灯示意图界面 。
创建并启动两个线程（东西向、南北向）同时运行
根据车流量进行控制。
该作业要求编程并调试通过。对你设计的类要有详细的文字说明（类所封装的内容，属性、方法的功能与含义等）。(. design a traffic signal light system:
Variable: position color (red yellow green)display time (second)
Method: switching signal lamp
Requirement
Design the intersection signal to show the intention interface.
Create and start two threads (east-west, north-south) running at the same time
Control according to the traffic flow.
This job requires programming and debugging through. There is a detailed descr iption of the class you have designed (the contents encapsulated in the class, the properties, the function and the meaning of the method, etc.).)