code: def tearDown(self):
      # just in case if we have transport close callbacks
      if not self.loop.is_closed():
          test_utils.run_briefly(self.loop)
  
      self.doCleanups()
      support.gc_collect()
      super().tearDown()
  
imports: import socket
  import asyncio
  import sys
  import unittest
  from asyncio import proactor_events
  from itertools import cycle, islice
  from unittest.mock import Mock
  from test.test_asyncio import utils
  from test import support
  from test.support import socket_helper
label_desc: Use image node_id 3 for calling the BaseSockTestsMixin obj's underlying member method code with example usage: obj.tearDown() without return types