code: def test_manifest_marker(self):
      # check that autogenerated MANIFESTs have a marker
      dist, cmd = self.get_cmd()
      cmd.ensure_finalized()
      cmd.run()
  
      f = open(cmd.manifest)
      try:
          manifest = [
              line.strip()
              for line in f.read().split("\n")
              if line.strip() != ""
          ]
      finally:
          f.close()
  
      self.assertEqual(
          manifest[0], "# file GENERATED by distutils, do NOT edit"
      )
  
imports: import os
  import tarfile
  import unittest
  import warnings
  import zipfile
  from os.path import join
  from textwrap import dedent
  from test.test_support import captured_stdout, check_warnings, run_unittest
  from distutils.command.sdist import sdist, show_formats
  from distutils.core import Distribution
  from distutils.tests.test_config import PyPIRCCommandTestCase
  from distutils.errors import DistutilsOptionError
  from distutils.spawn import find_executable
  from distutils.log import WARN
  from distutils.filelist import FileList
  from distutils.archive_util import ARCHIVE_FORMATS
label_desc: Use image node_id 18 for calling the SDistTestCase obj's underlying member method code with example usage: obj.test_manifest_marker() without return types