How to add wait

    public void YouWin()
    {
        if (Score >= 50)
        {
            Greenfoot.setWorld(new Space());
            Greenfoot.setWorld(new Next());
            
            Greenfoot.setWorld(new Space());
        }
    }

    public void YouWin2()
    {
        if (Score >= 100)
        {
            Greenfoot.setWorld(new Space());
            Greenfoot.setWorld(new Next());
            
            Greenfoot.setWorld(new Space());
        }  
    }

    public void YouWin3()
    {
        if (Score >= 200)
        {
            getWorld().addObject(new YouWin(), 300, 300);
        }  
    }