module command.remoteundostatus.stereoonwithcdcommand; import command.remoteundostatus.command; import command.remoteundostatus.stereo; class StereoOnWithCDCommand : Command { Stereo stereo; this(Stereo stereo) { this.stereo = stereo; } void execute() { stereo.on(); stereo.setCD(); stereo.setVolume(11); } void undo() { stereo.off(); } }