<｜begin▁of▁sentence｜>### Instruction:
Given a graph 'g', a color palette defined on its edges, and a Cairo context 'context', can you use DarkToLightEdgeDrawer to create edges that transition from dark to light color, and then render the graph to a PNG file called 'output.png'?
### Response:
import igraph as ig
import cairocffi as cairo
from igraph.drawing.edge import DarkToLightEdgeDrawer

# Assume we have an igraph Graph object defined as 'g'
# and a valid Cairo context called 'context'
g = ig.Graph.Famous('Zachary')
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 400, 400)
context = cairo.Context(surface)

# Instantiate a DarkToLightEdgeDrawer with a color palette
drawer = DarkToLightEdgeDrawer(context, palette=g.es['color'])

# Draw the graph and save the result to a file
layout = g.layout('kk')
g.draw(context, layout, edge_drawer=drawer)
surface.write_to_png('output.png')
<|EOT|>
