code: def test_manual_manifest(self):
      # check that a MANIFEST without a marker is left alone
      dist, cmd = self.get_cmd()
      cmd.formats = ["gztar"]
      cmd.ensure_finalized()
      self.write_file((self.tmp_dir, cmd.manifest), "README.manual")
      self.write_file(
          (self.tmp_dir, "README.manual"),
          "This project maintains its MANIFEST file itself.",
      )
      cmd.run()
      self.assertEqual(cmd.filelist.files, ["README.manual"])
  
      f = open(cmd.manifest)
      try:
          manifest = [
              line.strip()
              for line in f.read().split("\n")
              if line.strip() != ""
          ]
      finally:
          f.close()
  
      self.assertEqual(manifest, ["README.manual"])
  
      archive_name = join(self.tmp_dir, "dist", "fake-1.0.tar.gz")
      archive = tarfile.open(archive_name)
      try:
          filenames = [tarinfo.name for tarinfo in archive]
      finally:
          archive.close()
      self.assertEqual(
          sorted(filenames),
          ["fake-1.0", "fake-1.0/PKG-INFO", "fake-1.0/README.manual"],
      )
  
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 20 for calling the SDistTestCase obj's underlying member method code with example usage: obj.test_manual_manifest() without return types