编写一个类，描述桌子，包括以下几种属性：长、宽、高、颜色。并且使该类具有这样的功能：在定制桌子（即创建桌子对象时），就可以同时指定桌子的长宽高来订制。也可以同时指定长、宽、高、颜色来订制，也可单独指定桌子颜色来订制。

并编写一个测试类测试这几种定制方法。

-Write a class that describes the table, including the following properties: length, width, height, color. And so the class has a function: to customize the table (the table is created when an object), you can specify both the length and breadth of the table to order. You can also specify the length, width, height, color order, the table can also specify a separate color order. And write a test class to test these types of custom methods.