001package headfirst.command.party; 002 003public class StereoOnCommand implements Command { 004 Stereo stereo; 005 006 public StereoOnCommand(Stereo stereo) { 007 this.stereo = stereo; 008 } 009 010 public void execute() { 011 stereo.on(); 012 } 013 014 public void undo() { 015 stereo.off(); 016 } 017}