利用前面提到的SupplyDepot、Transport和CapableOfBeingRefefuelled类/接口，为Air-plane增加一个main()方法，然后为supplyDepot等增加必要的字段、参数和代码，以便CapableOfBeingRefefuelled能够告诉service（）方法需要加多少油。同时要确保Depot中的油应相应地减少，而实现CapableOfBeingRefefuelledi的类对象应相应地增加。(Using the upplyDepot, Transport and ApableOfBeingRefefuelled classes/interfaces mentioned above, add a main () method to Air-plane, and then add the necessary fields, parameters and codes to supplyDepot, so that CapableOfBeingRefefuelled can tell service () how much fuel the method needs. At the same time, we should ensure that the oil in Depot should be reduced accordingly, and the class objects that implement Capable OfBeingRefefuelledi should be increased accordingly.)