code: def setUp(self):
      # PyPIRCCommandTestCase creates a temp dir already
      # and put it in self.tmp_dir
      super(SDistTestCase, self).setUp()
      # setting up an environment
      self.old_path = os.getcwd()
      os.mkdir(join(self.tmp_dir, "somecode"))
      os.mkdir(join(self.tmp_dir, "dist"))
      # a package, and a README
      self.write_file((self.tmp_dir, "README"), "xxx")
      self.write_file((self.tmp_dir, "somecode", "__init__.py"), "#")
      self.write_file((self.tmp_dir, "setup.py"), SETUP_PY)
      os.chdir(self.tmp_dir)
  
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 1 for calling the SDistTestCase obj's underlying member method code with example usage: obj.setUp() without return types