<｜begin▁of▁sentence｜>### Instruction:
As an adventure guide leading a group on a hiking trip, a tourist wants to create a circular path on a map without outlining or filling it, using only the specified width as the diameter. They are seeking advice on how to customize the CircleDrawer class in the MapDrawer API to achieve this.
### Response:
import igraph as ig
import cairo

class CircleDrawer(ig.drawing.shapes.ShapeDrawer):
    def draw_path(self, context, width, height):
        context.arc(width / 2.0, height / 2.0, width / 2.0, 0, 2 * math.pi)

# Create a surface and context to draw on
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 250, 250)
context = cairo.Context(surface)

# Set line width
context.set_line_width(2)

# Instantiate CircleDrawer and draw circle
circle_drawer = CircleDrawer(context)
circle_drawer.draw_path(context, 100, 0)  # Height is ignored

# Stroke the path to draw the circle
context.stroke()

# Save the image
surface.write_to_png('circle.png')
<|EOT|>
