code: def gcs_listdir(dir_name: str) -> Optional[List[str]]:
      """List all files in the given GCS dir (`['dataset/1.0.0/file0', ...]`)."""
      root_dir = gcs_path(dir_name)
      if _is_gcs_disabled or not exists(root_dir):
          return None
      return [
          posixpath.join(dir_name, f.name) for f in root_dir.iterdir()
      ]
  
file_path: datasets/tensorflow_datasets/core/utils/gcs_utils.py
imports: import concurrent.futures
  import os
  import posixpath
  from typing import List, Optional
  from etils import epath
  from tensorflow_datasets.core.utils import py_utils
  from tensorflow_datasets.core.utils import tqdm_utils
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
label_desc: Use image node_id 4 for calling a global function with example usage: gcs_listdir(dir_name) and returns: unknown, None