code: def _read_list_from_msg(
      msg: Message, field: str
  ) -> Optional[List[str]]:
      """Read Message header field and return all results as list."""
      values = msg.get_all(field, None)
      if values == []:
          return None
      return values
  
imports: import os
  import stat
  import textwrap
  from email import message_from_file
  from email.message import Message
  from tempfile import NamedTemporaryFile
  from typing import Optional, List
  from distutils.util import rfc822_escape
  from .None import _normalization, _reqs
  from .extern.packaging.markers import Marker
  from .extern.packaging.requirements import Requirement
  from .extern.packaging.version import Version
  from .warnings import SetuptoolsDeprecationWarning
label_desc: Use image node_id 5 for calling a global function with example usage: _read_list_from_msg(msg, field) and returns: values, None