def from_persist_dir(
        cls,
        persist_dir: str = DEFAULT_PERSIST_DIR,
        namespace: Optional[str] = None,
        fs: Optional[fsspec.AbstractFileSystem] = None,
    ) -> "SimpleDocumentStore":
        """
        Create a SimpleDocumentStore from a persist directory.

        Args:
            persist_dir (str): directory to persist the store
            namespace (Optional[str]): namespace for the docstore
            fs (Optional[fsspec.AbstractFileSystem]): filesystem to use

        """
        if fs is not None:
            persist_path = concat_dirs(persist_dir, DEFAULT_PERSIST_FNAME)
        else:
            persist_path = os.path.join(persist_dir, DEFAULT_PERSIST_FNAME)
        return cls.from_persist_path(persist_path, namespace=namespace, fs=fs)

        Create a SimpleDocumentStore from a persist directory.

        Args:
            persist_dir (str): directory to persist the store
            namespace (Optional[str]): namespace for the docstore
            fs (Optional[fsspec.AbstractFileSystem]): filesystem to use

        
llama-index-core/llama_index/core/storage/docstore/simple_docstore.py