code: def test_existing_niftynet_home_not_touched(self):
      niftynet_home = expanduser(
          NiftyNetGlobalConfigTestBase.default_config_opts["home"]
      )
      makedirs(niftynet_home)
      niftynet_ext = join(
          niftynet_home,
          NiftyNetGlobalConfigTestBase.default_config_opts["ext"],
      )
      makedirs(niftynet_ext)
      niftynet_ext_init = join(niftynet_ext, "__init__.py")
      open(niftynet_ext_init, "w").close()
      mtime_before = getmtime(niftynet_ext_init)
  
      global_config = NiftyNetGlobalConfig()
  
      mtime_after = getmtime(niftynet_ext_init)
      self.assertEqual(mtime_before, mtime_after)
  
imports: from glob import glob
  from os import remove, makedirs
  from os.path import expanduser, join, isdir, isfile
  from os.path import getmtime
  from shutil import rmtree
  from unittest import TestCase
  from niftynet.utilities.niftynet_global_config import NiftyNetGlobalConfig
label_desc: Use image node_id 1 for calling the TestExistingNiftynetHomeNotTouched obj's underlying member method code with example usage: obj.test_existing_niftynet_home_not_touched() without return types