code: def testChangeWorkingDir(self):
      cwd = os.getcwd()
      new_cwd = os.path.join(self.tmp_dir, "new")
      os.makedirs(new_cwd)
      with test_case_utils.change_working_dir(new_cwd) as old_cwd:
          self.assertEqual(
              os.path.realpath(old_cwd), os.path.realpath(cwd)
          )
          self.assertEqual(
              os.path.realpath(new_cwd), os.path.realpath(os.getcwd())
          )
  
      self.assertEqual(
          os.path.realpath(cwd), os.path.realpath(os.getcwd())
      )
  
imports: import copy
  import os
  import unittest
  import tensorflow
  from tfx import types
  from tfx.types import standard_artifacts
  from tfx.utils import test_case_utils
label_desc: Use image node_id 4 for calling the TestCaseUtilsTest obj's underlying member method code with example usage: obj.testChangeWorkingDir() without return types