code: def test_list_data_directory_no_revision(self):
      files = self.hffs.ls(self.hf_path + "/data")
      self.assertEqual(len(files), 2)
  
      self.assertEqual(files[0]["type"], "file")
      self.assertGreater(files[0]["size"], 0)  # not empty
      self.assertTrue(
          files[0]["name"].endswith("/data/binary_data.bin")
      )
      self.assertIsNotNone(files[0]["lfs"])
      self.assertIn("sha256", files[0]["lfs"])
      self.assertIn("size", files[0]["lfs"])
      self.assertIn("pointer_size", files[0]["lfs"])
      self.assertIsNotNone(files[0]["last_commit"])
      self.assertIsNotNone(files[0]["blob_id"])
      self.assertIn(
          "security", files[0]
      )  # the staging endpoint does not run security checks
  
      self.assertEqual(files[1]["type"], "file")
      self.assertGreater(files[1]["size"], 0)  # not empty
      self.assertTrue(files[1]["name"].endswith("/data/text_data.txt"))
      self.assertIsNone(files[1]["lfs"])
      self.assertIsNotNone(files[1]["last_commit"])
      self.assertIsNotNone(files[1]["blob_id"])
      self.assertIn("security", files[1])
  
imports: import datetime
  import unittest
  from typing import Optional
  from unittest.mock import patch
  import fsspec
  import pytest
  from huggingface_hub.hf_file_system import HfFileSystem
  from huggingface_hub.utils import RepositoryNotFoundError, RevisionNotFoundError
  from .testing_constants import ENDPOINT_STAGING, TOKEN
  from .testing_utils import repo_name
label_desc: Use image node_id 18 for calling the HfFileSystemTests obj's underlying member method code with example usage: obj.test_list_data_directory_no_revision() without return types