class_docstr: Variant of ChainMap that allows direct updates to inner scopes.
  
  Only works when all passed mapping are mutable.
class_docstr_tok: ["Variant","of","ChainMap","that","allows","direct","updates","to","inner","scopes",".","Only","works","when","all","passed","mapping","are","mutable","."]
code: def __setitem__(self, key: _KT, value: _VT) -> None:
      for mapping in self.maps:
          if key in mapping:
              mapping[key] = value
              return
      self.maps[0][key] = value
  
imports: from __future__ import annotations
  import datetime
  import inspect
  from io import StringIO
  import itertools
  import pprint
  import struct
  import sys
  from typing import ChainMap, TypeVar
  import numpy
  from pandas._libs.tslibs import Timestamp
  from pandas.errors import UndefinedVariableError
label_desc: Use image node_id 1 for calling the DeepChainMap obj's underlying member method code with example usage: obj.__setitem__(key, value) without return types