code: def can_dac_override():
      global _can_dac_override
  
      if not can_chmod():
          _can_dac_override = False
      if _can_dac_override is not None:
          return _can_dac_override
  
      try:
          with open(TESTFN, "wb") as f:
              os.chmod(TESTFN, 0o400)
              try:
                  with open(TESTFN, "wb"):
                      pass
              except OSError:
                  _can_dac_override = False
              else:
                  _can_dac_override = True
      finally:
          try:
              os.chmod(TESTFN, 0o700)
          except OSError:
              pass
          unlink(TESTFN)
  
      return _can_dac_override
  
imports: import collections.abc
  import contextlib
  import errno
  import os
  import re
  import stat
  import string
  import sys
  import time
  import unittest
  import warnings
  from test import support
label_desc: Use image node_id 8 for calling a global function with example usage: can_dac_override() and returns: _can_dac_override, _can_dac_override