Method __delitem__

src/werkzeug/datastructures/headers.py:257–262

(self, key: str | int | slice)

            self.add(key, value)

    def __delitem__(self, key: str | int | slice) -> None:
        if isinstance(key, str):
            self._del_key(key)
            return

        del self._list[key]

    def _del_key(self, key: str) -> None:
        key = key.lower()