<｜begin▁of▁sentence｜>### Instruction:
Given a graph whose edge set is [(1, 2), (1, 3), (2, 3), (3, 4), (4, 5), (5, 6), (6, 1)], use NetworkX to determine if the graph is a tree.
### Response:
import networkx as nx

# Create a Graph object
G = nx.Graph()

# Add edges
G.add_edges_from([(1, 2), (1, 3), (2, 3), (3, 4), (4, 5), (5, 6), (6, 1)])

# Check if the graph is a tree
is_tree = nx.is_tree(G)

# Output the result
print("The graph is a tree:" if is_tree else "The graph is not a tree")
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