docs: def draw_tiling(coord_generator, filename):
      """Given a coordinate generator and a filename, render those coordinates in
      a new image and save them to the file."""
      im = Image.new('L', size=(CANVAS_WIDTH, CANVAS_HEIGHT))
      for shape in coord_generator(CANVAS_WIDTH, CANVAS_HEIGHT):
          ImageDraw.Draw(im).polygon(shape, outline='white')
      im.save(filename)