<｜begin▁of▁sentence｜>### Instruction:
Given two full balanced binary trees of height 2, can you join these trees into one larger tree with a new root node, ensuring the original node labels are kept as an attribute?
### Response:
import networkx as nx

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

# Specify the root nodes for left and right trees
left_root = 0
right_root = 0

# Join the trees with a new root node
joined_tree = nx.join_trees([(left_tree, left_root), (right_tree, right_root)], label_attribute='old_label')

# Print information about the joined tree
print(nx.info(joined_tree))
print('New root node:', joined_tree.nodes(data=True))
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