code: def tearDown(self):
      super().tearDown()
      config.tls.config = config.main_thread_config = self._before
      del self._before
  
imports: from concurrent import futures
  import inspect
  import threading
  from absl.testing import absltest
  from absl.testing import parameterized
  from haiku._src import config
label_desc: Use image node_id 2 for calling the ConfigTest obj's underlying member method code with example usage: obj.tearDown() without return types