Команда (Command) с добавлением микроволновки

using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Linq;
using System.Threading.Tasks;

class Program
{
   static void Main(string[] args)
   {
    var pult = new Pult();
    var tv = new TV();
    var mcrwln = new Microwave();

    pult.SetCommand(new TVOnCommand(tv));

    pult.PressButton();
    pult.PressUndo();

    pult.SetCommand(new MicrowaveCommand(mcrwln, 3000));
    pult.PressButton();
//      pult.PressUndo();

    Console.ReadLine();
   }
}

interface ICommand
{
    void Execute();
    void Undo();
}

class TV
{
    public void On()
    {
        Console.WriteLine("Телевизор включен");
    }

    public void Off()
    {
        Console.WriteLine("Телевизор выключен");
    }
}

class TVOnCommand: ICommand
{
    TV tv;

    public TVOnCommand(TV tvSet)
    {
        this.tv = tvSet;
    }

    public void Execute()
    {
        tv.On();
    }

    public void Undo()
    {
        tv.Off();
    }
}

class Pult
{
    ICommand command;

    public Pult(){}

    public void SetCommand(ICommand com)
    {
        this.command = com;
    }

    public void PressButton()
    {
        this.command.Execute();
    }

    public void PressUndo()
    {
        this.command.Undo();
    }
}

class Microwave
{
    public void StartCooking(int time)
    {
        Console.WriteLine("Подогреваем еду. Осталось: {0} секунд: ", time/1000);
        Thread.Sleep(time);
        Console.WriteLine("Еда готова");
    }

    public void StopCooking()
    {
        Console.WriteLine("Микроволновка выключена");
    }
}

class MicrowaveCommand: ICommand
{
    Microwave microwave;
    int time;

    public MicrowaveCommand(Microwave m, int t)
    {
        this.microwave = m;
        this.time = t;
    }

    public void Execute()
    {
        this.microwave.StartCooking(this.time);
    }

    public void Undo()
    {
        this.microwave.StopCooking();
    }
}