Method update

httpx/_models.py:274–279

(self, headers: HeaderTypes | None = None)

        return split_values

    def update(self, headers: HeaderTypes | None = None) -> None:  class="cm"># type: ignore
        headers = Headers(headers)
        for key in headers.keys():
            if key in self:
                self.pop(key)
        self._list.extend(headers._list)

    def copy(self) -> Headers:
        return Headers(self, encoding=self.encoding)