package headfirst.command.party;public class CeilingFanMediumCommand implements Command {	CeilingFan ceilingFan;	int prevSpeed;	public CeilingFanMediumCommand(CeilingFan ceilingFan) {		this.ceilingFan = ceilingFan;	}	public void execute() {		prevSpeed = ceilingFan.getSpeed();		ceilingFan.medium();	}	public void undo() {		switch (prevSpeed) {			case CeilingFan.HIGH: 	ceilingFan.high(); break;			case CeilingFan.MEDIUM: ceilingFan.medium(); break;			case CeilingFan.LOW: 	ceilingFan.low(); break;			default: 				ceilingFan.off(); break;		}	}}