<｜begin▁of▁sentence｜>### Instruction:
Given a tree graph represented by an igraph Graph object 'g', how can you use the layout_reingold_tilford_circular function to generate and visualize a circular Reingold-Tilford layout for this tree?
### Response:
from igraph import Graph

# Assuming 'g' is a Graph object representing a tree
layout = g.layout_reingold_tilford_circular()
# Plot the graph using the layout
igraph.plot(g, layout=layout)
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