# Copyright (C) 2002-2006 Python Software Foundation# Author: Barry Warsaw# Contact: email-sig@python.org """Base class for MIME type messages that are not multipart.""" __all__ = ['MIMENonMultipart'] from email import errorsfrom email.mime.base import MIMEBase  class MIMENonMultipart(MIMEBase):    """Base class for MIME multipart/* type messages."""     __pychecker__ = 'unusednames=payload'     def attach(self, payload):        # The public API prohibits attaching multiple subparts to MIMEBase        # derived subtypes since none of them are, by definition, of content        # type multipart/*        raise errors.MultipartConversionError(            'Cannot attach additional subparts to non-multipart/*')     del __pychecker__