code: def _correct_folder(folder: str) -> str:
      """Ensures the folder follows a standard.
  
      Pathlib.parent in the root folder results in '.', whereas in other places
      we should use '' for the root folder. This function makes sure the root
      folder is always empty string.
  
      Args:
        folder: the folder to be corrected.
  
      Returns:
        The corrected folder.
      """
      if folder == ".":
          return ""
      return folder
  
imports: import dataclasses
  import functools
  import os
  import pathlib
  import posixpath
  from typing import Iterator, Mapping, MutableMapping, Optional, Set, Tuple
  from etils import epath
  import requests
  from tensorflow_datasets.core import utils
label_desc: Use image node_id 3 for calling a global function with example usage: _correct_folder(folder) and returns: folder, str