def persist(
        self,
        persist_path: str = DEFAULT_PERSIST_PATH,
        fs: Optional[fsspec.AbstractFileSystem] = None,
    ) -> None:
        """
        Save to file.

        This method saves the vector store to disk.

        Args:
            persist_path (str): The save_path of the file.

        """
        super().persist(persist_path=persist_path, fs=fs)
        dirpath = os.path.dirname(persist_path)
        if not os.path.exists(dirpath):
            os.makedirs(dirpath)

        id_map = {}
        id_map["node_id_to_faiss_id_map"] = self._node_id_to_faiss_id_map
        id_map["faiss_id_to_node_id_map"] = self._faiss_id_to_node_id_map
        # save the id map
        id_map_path = os.path.join(dirpath, DEFAULT_ID_MAP_NAME)
        with open(id_map_path, "w") as f:
            f.write(str(id_map))

        Save to file.

        This method saves the vector store to disk.

        Args:
            persist_path (str): The save_path of the file.

        
llama-index-integrations/vector_stores/llama-index-vector-stores-faiss/llama_index/vector_stores/faiss/map_store.py