code: def print_bintree(tree, indent="  "):
      """print a binary tree"""
      for n in sorted(tree.keys()):
          print(f"{indent * depth(n, tree)}{n}")
  
imports: import re
  import socket
  from functools import reduce
  import zmq
  from ipyparallel.serialize import deserialize_object, serialize_object
  from ipyparallel.util import disambiguate_url
label_desc: Use image node_id 4 for calling a global function with example usage: print_bintree(tree, indent) without return types