code: def test_check_archive_formats(self):
      self.assertEqual(
          check_archive_formats(["gztar", "xxx", "zip"]), "xxx"
      )
      self.assertEqual(check_archive_formats(["gztar", "zip"]), None)
  
imports: import unittest
  import os
  import sys
  import tarfile
  from os.path import splitdrive
  import warnings
  from distutils.archive_util import check_archive_formats, make_tarball, make_zipfile, make_archive, ARCHIVE_FORMATS
  from distutils.spawn import find_executable, spawn
  from distutils.tests import support
  from test.test_support import check_warnings, run_unittest
label_desc: Use image node_id 8 for calling the ArchiveUtilTestCase obj's underlying member method code with example usage: obj.test_check_archive_formats() without return types