code: def parse_treebanks(st):
      """Returns the corresponding tree of the treebank, in the form of
      a nested dictionary
      :param st: str: treebank using Penn notation
      """
      d = dict()
      for path in get_paths(st):
          set_path(d, path[:-1], path[-1])
      return d
  
label_desc: Use image node_id 3 for calling a global function with example usage: parse_treebanks(st) and returns: d