code: def _test_single(self, filename):
      remove_if_exists(filename)
      create_empty_file(filename)
      try:
          self._do_single(filename)
      finally:
          os.unlink(filename)
      self.assertTrue(not os.path.exists(filename))
      # and again with os.open.
      f = os.open(filename, os.O_CREAT | os.O_WRONLY)
      os.close(f)
      try:
          self._do_single(filename)
      finally:
          os.unlink(filename)
  
file_path: cpython/Lib/test/test_unicode_file.py
imports: import os, glob, time, shutil
  import sys
  import unicodedata
  import unittest
  from test.support.os_helper import rmtree, change_cwd, TESTFN_UNICODE, TESTFN_UNENCODABLE, create_empty_file
label_desc: Use image node_id 4 for calling the TestUnicodeFiles obj's underlying member method code with example usage: obj._test_single(filename) without return types