def __init__(
self, favicon_url_path: str, favicon_file_path: str,
request_path_provider: Callable[[Dict], Optional[str]]) -> None:
super().__init__()
favicon_whitenoise = WhiteNoise(None)
favicon_static_file = favicon_whitenoise.get_static_file(
path=favicon_file_path, url=favicon_url_path)
favicon_whitenoise.files[favicon_url_path] = favicon_static_file
self._favicon_url_path = favicon_url_path
self._favicon_handler = partial(favicon_whitenoise.serve,
static_file=favicon_static_file)
self._request_path_provider = request_path_provider
