<｜begin▁of▁sentence｜>### Instruction:
Suppose you have two full balanced binary trees, each with a height of 4. How would you join them into a new tree with a new root, ensuring that the new tree becomes a full balanced binary tree of height 5? The original node labels must be preserved under a new attribute during the join.
### Response:
import networkx as nx

# Create two full balanced binary trees with height 4
left_tree = nx.balanced_tree(2, 4)
right_tree = nx.balanced_tree(2, 4)

# Join the two trees with a new root node
# The new root node has the default starting label of 0
joined_tree = nx.join_trees([left_tree, right_tree], label_attribute='old_label', first_label=1)

# Check if the joined tree is isomorphic to a full balanced binary tree of height 5
print(nx.is_isomorphic(joined_tree, nx.balanced_tree(2, 5)))

# Print the edges of the new tree to visualize its structure
print(joined_tree.edges(data=True))
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