code: def _add_defaults_optional(self):
      optional = ["test/test*.py", "setup.cfg"]
      for pattern in optional:
          files = filter(os.path.isfile, glob(pattern))
          self.filelist.extend(files)
  
imports: import os
  import sys
  from glob import glob
  from warnings import warn
  from distutils.core import Command
  from distutils import dir_util
  from distutils import file_util
  from distutils import archive_util
  from distutils.text_file import TextFile
  from distutils.filelist import FileList
  from distutils import log
  from distutils.util import convert_path
  from distutils.errors import DistutilsTemplateError, DistutilsOptionError
label_desc: Use image node_id 10 for calling the sdist obj's underlying member method code with example usage: obj._add_defaults_optional() without return types