<｜begin▁of▁sentence｜>### Instruction:
The data used in the code includes a graph created with the networkx path_graph function, consisting of 4 nodes arranged in a path. The problem solved by the code is the visualization of this graph's nodes positioned in concentric circles, according to the specified shell arrangement. In this case, node 0 is placed at the center, and nodes 1, 2, and 3 are arranged in a shell around it. The nodes are then drawn using Matplotlib, showcasing the shell layout.
### Response:
import networkx as nx
import matplotlib.pyplot as plt

# Create a graph
G = nx.path_graph(4)

# Specify shell arrangement
shells = [[0], [1, 2, 3]]

# Apply shell layout
pos = nx.shell_layout(G, shells)

# Draw the graph
nx.draw(G, pos, with_labels=True)
plt.show()
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