code: def round_rectangle(size, radius, fill):
      
      width, height = size
      rectangle = Image.new('L', size, 255)  # fill
      corner = round_corner(radius, 255)  # fill
      rectangle.paste(corner, (0, 0))
      rectangle.paste(corner.rotate(90),
                      (0, height - radius))  # Rotate the corner and paste it
      rectangle.paste(corner.rotate(180), (width - radius, height - radius))
      rectangle.paste(corner.rotate(270), (width - radius, 0))
      return rectangle
docs: Draw a rounded rectangle