code: def __delattr__(self, key: str) -> None:
      if key in {"default", "rebuild", "valid_types"}:
          msg = f"{self.__class__.__name__!r} object does not support deletion of {key!r}"
          raise TypeError(msg)
      super().__delattr__(key)
  
imports: from __future__ import annotations
  import sys
  import time
  import traceback
  import types
  import warnings
  from os import getenv, path
  from typing import TYPE_CHECKING, Any, Literal, NamedTuple, Union
  from sphinx.deprecation import RemovedInSphinx90Warning
  from sphinx.errors import ConfigError, ExtensionError
  from sphinx.locale import _, __
  from sphinx.util import logging
  from sphinx.util.osutil import fs_encoding
  from sphinx.util.typing import NoneType
label_desc: Use image node_id 7 for calling the _Opt obj's underlying member method code with example usage: obj.__delattr__(key) without return types