code: def change(img):
      
      if not os.path.isfile(img):
          return
  
      desktop = get_desktop_env()
  
      if OS == "Darwin":
          set_mac_wallpaper(img)
  
      elif OS == "Windows":
          set_win_wallpaper(img)
  
      else:
          set_desktop_wallpaper(desktop, img)
  
      logging.info("Set the new wallpaper.")
docs: Set the wallpaper.