code: def tearDown(self) -> None:
      super().tearDown()
  
      secrets_singleton._reset()
      _resource_caches.clear_all()
  
      os.environ.clear()
      os.environ.update(self._prev_environ)
  
imports: import os
  import sys
  import threading
  import unittest
  from unittest.mock import MagicMock, mock_open, patch
  import pytest
  from parameterized import parameterized
  from streamlit.connections import BaseConnection, SnowflakeConnection, SnowparkConnection, SQLConnection
  from streamlit.errors import StreamlitAPIException
  from streamlit.runtime.caching.cache_resource_api import _resource_caches
  from streamlit.runtime.connection_factory import _create_connection, _get_first_party_connection, connection_factory
  from streamlit.runtime.scriptrunner import add_script_run_ctx
  from streamlit.runtime.secrets import secrets_singleton
  from tests.testutil import create_mock_script_run_ctx
label_desc: Use image node_id 2 for calling the ConnectionFactoryTest obj's underlying member method code with example usage: obj.tearDown() without return types