code: def tearDown(self):
      if self.old is None:
          os.environ.pop(visible)
      else:
          os.environ[visible] = self.old
  
imports: import operator
  import os
  import shutil
  import subprocess
  import sys
  import tempfile
  import unittest
  from unittest import mock
  import numpy
  import pytest
  import cupy
  import cupyx
label_desc: Use image node_id 2 for calling the TestNotAvailable obj's underlying member method code with example usage: obj.tearDown() without return types