code: def case_insensitive_tests(test):
      """Class decorator that nullifies tests requiring a case-insensitive
      file system."""
      return unittest.skipIf(
          not CASE_INSENSITIVE_FS,
          "requires a case-insensitive filesystem",
      )(test)
  
imports: import builtins
  import contextlib
  import errno
  import functools
  from importlib import machinery, util, invalidate_caches
  import marshal
  import os
  import os.path
  from test.support import import_helper
  from test.support import os_helper
  import unittest
  import sys
  import tempfile
  import types
label_desc: Use image node_id 6 for calling a global function with example usage: case_insensitive_tests(test) and returns: unittest