code: def test_saver_flag_separate_dirs(
      self,
      metadata_update,
      mock_upload_file,
      mock_upload,
      mock_download,
      mock_create,
  ):
      with tempfile.TemporaryDirectory() as tmpdirname:
          io = gr.Interface(
              lambda x: x,
              "text",
              "text",
              flagging_dir=tmpdirname,
              flagging_callback=flagging.HuggingFaceDatasetSaver(
                  "test", "test", separate_dirs=True
              ),
          )
          row_count = io.flagging_callback.flag(["test", "test"], "")
          assert row_count == 1  # 2 rows written including header
          row_count = io.flagging_callback.flag(["test", "test"])
          assert row_count == 2  # 3 rows written including header
          for _, _, filenames in os.walk(tmpdirname):
              for f in filenames:
                  fname = os.path.basename(f)
                  assert fname in [
                      "metadata.jsonl",
                      "dataset_info.json",
                  ] or fname.endswith(".lock")
  
imports: import os
  import tempfile
  from unittest.mock import MagicMock, patch
  import pytest
  import gradio
  from gradio import flagging
label_desc: Use image node_id 3 for calling the TestHuggingFaceDatasetSaver obj's underlying member method code with example usage: obj.test_saver_flag_separate_dirs(metadata_update, mock_upload_file, mock_upload, mock_download, mock_create) without return types