<｜begin▁of▁sentence｜>### Instruction:
Given an undirected Erdős-Rényi graph with 10 vertices and 15 edges, how can you visualize an undirected edge between two points (100, 200) and (400, 350) with a width ratio of 0.6 using the TaperedEdgeDrawer in igraph and save it to a PNG image?
### Response:
from igraph import Graph, plot
from igraph.drawing.edge import TaperedEdgeDrawer
import cairo

g = Graph.Erdos_Renyi(n=10, m=15)

# Create a plot surface
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 600, 400)
context = cairo.Context(surface)

# Create a plot with custom edge drawer
custom_drawer = TaperedEdgeDrawer(context)

# Draw an undirected edge using the custom edge drawer
custom_drawer.draw_undirected_edge((100, 200), (400, 350), 0.6)

# Save to a file
surface.write_to_png('undirected_edge.png')
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