<｜begin▁of▁sentence｜>### Instruction:
Given a tree graph with 7 vertices where each non-leaf vertex has 2 children, can you use the Reingold-Tilford layout algorithm in igraph to arrange the vertices and plot the tree structure?
### Response:
import igraph as ig

# Load a graph
graph = ig.Graph.Tree(7, 2)

# Apply the Reingold-Tilford layout algorithm
layout = graph.layout_reingold_tilford()

# Plot the graph
ig.plot(graph, layout=layout, target='tree_layout.png')
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