code: def logic_key(self):
      if not hasattr(self, "_logic_key") or self._logic_key is None:
          token_keys = []
          for node in self.bfs():
              logic_key = node.op.get_logic_key()
              if (
                  hasattr(node.op, "logic_key")
                  and node.op.logic_key is None
              ):
                  node.op.logic_key = logic_key
              token_keys.append(
                  tokenize(logic_key, **node.extra_params)
                  if node.extra_params
                  else logic_key
              )
          self._logic_key = tokenize(*token_keys)
      return self._logic_key
  
imports: from abc import ABCMeta, abstractmethod
  from typing import List, Dict, Tuple, Union, Iterable
  from ...core import Tileable, Chunk
  from ...serialization.core import buffered
  from ...serialization.serializables import Serializable, DictField, ListField, BoolField
  from ...serialization.serializables.core import SerializableSerializer
  from ...utils import tokenize
  from .core import DAG
label_desc: Use image node_id 5 for calling the TileableGraph obj's underlying member method code with example usage: obj.logic_key() and returns: self