code: def __str__(self) -> str:
      return (
          f"name: {self.name}\n"
          + f"par: {self.par.name if self.par is not None else None}\n"
          + f"level: {self.level}\n"
          + f"iso: {self.iso}\n"
          + f"ancestors: {[node.name for node in self.get_ancestors()]}\n"
      )
  
imports: import json
  from typing import Dict, List, Union
label_desc: Use image node_id 2 for calling the LeafNode obj's underlying member method code with example usage: obj.__str__() and returns: unknown