class_docstr: Mapping proxy that delays resolving the target object, until really needed.
  
  >>> def obtain_mapping():
  ...     print("Running expensive function!")
  ...     return {"key": "value", "other key": "other value"}
  >>> mapping = LazyMappingProxy(obtain_mapping)
  >>> mapping["key"]
  Running expensive function!
  'value'
  >>> mapping["other key"]
  'other value'
class_docstr_tok: ["Mapping","proxy","that","delays","resolving","the","target","object",",","until","really","needed",".",">",">",">","def","obtain_mapping","(",")",":","...","print","(","``","Running","expensive","function","!","''",")","...","return","{","``","key","''",":","``","value","''",",","``","other","key","''",":","``","other","value","''","}",">",">",">","mapping","=","LazyMappingProxy","(","obtain_mapping",")",">",">",">","mapping","[","``","key","''","]","Running","expensive","function","!","'value'",">",">",">","mapping","[","``","other","key","''","]","'other","value","'"]
code: def __getitem__(self, key: _K) -> _V:
      return self._target()[key]
  
imports: import ast
  import importlib
  import os
  import pathlib
  import sys
  from glob import iglob
  from configparser import ConfigParser
  from importlib.machinery import ModuleSpec
  from itertools import chain
  from typing import TYPE_CHECKING, Callable, Dict, Iterable, Iterator, List, Mapping, Optional, Tuple, TypeVar, Union, cast
  from pathlib import Path
  from types import ModuleType
  from distutils.errors import DistutilsOptionError
  from .._path import same_path
  from ..warnings import SetuptoolsWarning
label_desc: Use image node_id 3 for calling the LazyMappingProxy obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self