def METHOD_NAME(output_dir):
    """
    test drawing polygons to the background
    """
    mc = MapCanvas((400, 300), preset_colors='web')
    mc.background_color = 'transparent'
    mc.clear_background()
    mc.draw_polyline(((-30, 30),
                      (30, 30),
                      (30, -20),
                      (-30, -20)),
                     line_color='red',
                     line_width=5,
                     background=False)
    mc.save_foreground(os.path.join(output_dir, "foreground_polyline.png"))