code: def tearDownClass(cls):
      del os.environ["TZ"]
      if cls.tz_prev is not None:
          os.environ["TZ"] = cls.tz_prev
      time.tzset()
      ReusedSQLTestCase.tearDownClass()
  
imports: import os
  import time
  import unittest
  from pyspark.errors import PythonException
  from pyspark.sql import Row
  from pyspark.sql.functions import col
  from pyspark.testing.sqlutils import ReusedSQLTestCase, have_pyarrow, pyarrow_requirement_message
  from pyspark.testing.utils import QuietTest
label_desc: Use image node_id 2 for calling the CogroupedMapInArrowTests obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types