code: def tearDown(self) -> None:
      self._test_dir.cleanup()
  
imports: import tempfile
  import unittest
  from unittest.mock import MagicMock, mock_open, patch
  from streamlit.watcher import util
label_desc: Use image node_id 2 for calling the DirHelperTests obj's underlying member method code with example usage: obj.tearDown() without return types