How to use the rss2email.email function in rss2email

if ':' in header:
                    key,value = header.split(':', 1)
                    extra_headers[key.strip()] = value.strip()
                else:
                    _LOG.warning(
                        'malformed bonus-header: {}'.format(
                            self.bonus_header))

        content = self._get_entry_content(entry)
        try:
            content = self._process_entry_content(
                entry=entry, content=content, subject=subject)
        except _error.ProcessingError as e:
            e.parsed = parsed
            raise
        message = _email.get_message(
            sender=sender,
            recipient=self.to,
            subject=subject,
            body=content['value'],
            content_type=content['type'].split('/', 1)[1],
            extra_headers=extra_headers,
            config=self.config,
            section=self.section)
        return (guid, guid, sender, message)

def _send(self, sender, message):
        _LOG.info('send message for {}'.format(self))
        section = self.section
        if section not in self.config:
            section = 'DEFAULT'
        _email.send(sender=sender, recipient=self.to, message=message,
                    config=self.config, section=section)

b'Subject: Homage'
    b'Content-Transfer-Encoding: 8bit'
    b''
    b"\x00Y\x00o\x00u\x00'\x00r\x00e\x00 \x00g\x00r\x00e\x00a\x00t\x00,\x00 \x00\x96\x03\xb5\x03\xcd\x03\xc2\x03!\x00\n\x00"
    """
    bytesio = _io.BytesIO()
    # TODO: use policies argument instead of policy set in `message`
    # see https://docs.python.org/3.5/library/email.generator.html?highlight=bytesgenerator#email.generator.BytesGenerator
    generator = _BytesGenerator(bytesio)
    try:
        generator.flatten(message)
    except UnicodeEncodeError as e:
        # HACK: work around deficiencies in BytesGenerator
        _LOG.warning(e)
        b = message.as_string().encode(str(message.get_charset()))
        m = _email.message_from_bytes(b)
        if not m:
            raise
        h = {k:_decode_header(v) for k,v in m.items()}
        head = {k:_decode_header(v) for k,v in message.items()}
        body = str(m.get_payload(decode=True), str(m.get_charsets()[0]))
        if (h == head and body == message.get_payload()):
            return b
        raise
    else:
        return bytesio.getvalue()

A very simple function that decodes the entry into a unicode
    string and then calls BeautifulSoup on it and afterwards encodes
    the feed entry
    """
    # decode message
    encoding = message.get_charsets()[0]
    content = str(message.get_payload(decode=True), encoding)

    # modify content
    soup = BeautifulSoup(content)
    content = soup.prettify()

    # BeautifulSoup uses unicode, so we perhaps have to adjust the encoding.
    # It's easy to get into encoding problems and this step will prevent
    # them ;)
    encoding = rss2email.email.guess_encoding(content, encodings=feed.encodings)

    # clear CTE and set message. It can be important to clear the CTE
    # before setting the payload, since the payload is only re-encoded
    # if CTE is not already set.
    del message['Content-Transfer-Encoding']
    message.set_payload(content, charset=encoding)
    return message