def from_config_file(fn: str) -> "YAuth":
        """
        Create a YAuth instance from a configuration file.

        :param fn: Path to the JSON configuration file.
        :return: A YAuth instance.
        """
        with open(fn, encoding="utf-8") as f:
            js = json.load(f)
        return YAuth.from_dict(js)

        Create a YAuth instance from a configuration file.

        :param fn: Path to the JSON configuration file.
        :return: A YAuth instance.
        
llama-index-integrations/embeddings/llama-index-embeddings-yandexgpt/llama_index/embeddings/yandexgpt/util.py