docstr: Write the file list in 'self.filelist' (presumably as filled in
  by 'add_defaults()' and 'read_template()') to the manifest file
  named by 'self.manifest'.
code: def write_manifest(self):
      """Write the file list in 'self.filelist' (presumably as filled in
      by 'add_defaults()' and 'read_template()') to the manifest file
      named by 'self.manifest'.
      """
      if self._manifest_is_not_generated():
          log.info(
              "not writing to manually maintained "
              "manifest file '%s'" % self.manifest
          )
          return
  
      content = self.filelist.files[:]
      content.insert(0, "# file GENERATED by distutils, do NOT edit")
      self.execute(
          file_util.write_file,
          (self.manifest, content),
          "writing manifest file '%s'" % self.manifest,
      )
  
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 18 for calling the sdist obj's underlying member method code with example usage: obj.write_manifest() without return types