docstr: Remove the header ``key``.
code: def __delitem__(self, key: str) -> None:
      """
      Remove the header ``key``.
      """
  
imports: from __future__ import annotations
  import contextlib
  import contextvars
  import os
  import typing
  from abc import ABC
  from abc import abstractmethod
  from typing import TYPE_CHECKING
  import attr
  import starlette.datastructures
  from .utils.http import Cookie
label_desc: Use image node_id 2 for calling the Metadata obj's underlying member method code with example usage: obj.__delitem__(key) without return types