How to use the rss2email.LOG.warning function in rss2email

('X-RSS-Feed', self.url),
                ('X-RSS-ID', guid),
                ('X-RSS-URL', self._get_entry_link(entry)),
                ('X-RSS-TAGS', self._get_entry_tags(entry)),
                ))
        # remove empty tags, etc.
        keys = {k for k, v in extra_headers.items() if v is None}
        for key in keys:
            extra_headers.pop(key)
        if self.bonus_header:
            for header in self.bonus_header.splitlines():
                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],

def log(self):
        super(IMAPConnectionError, self).log()
        _LOG.warning(
            'check your config file to confirm that imap-server and other '
            'mail server settings are configured properly')
        if hasattr(self.__cause__, 'reason'):
            _LOG.error('reason: {}'.format(self.__cause__.reason))

def log(self):
        super(ProcessingError, self).log()
        if type(self) == ProcessingError:  # not a more specific subclass
            _LOG.warning(
                '=== rss2email encountered a problem with this feed ===')
            _LOG.warning(
                '=== See the rss2email FAQ at {} for assistance ==='.format(
                    __url__))
            _LOG.warning(
                '=== If this occurs repeatedly, send this to {} ==='.format(
                    __email__))
            _LOG.warning(
                'error: {} {}'.format(
                    self.parsed.get('bozo_exception', "can't process"),
                    self.feed.url))
            _LOG.warning(_pprint.pformat(self.parsed))
            _LOG.warning('rss2email {}'.format(__version__))
            _LOG.warning('feedparser {}'.format(_feedparser.__version__))
            _LOG.warning('html2text {}'.format(_html2text.__version__))
            _LOG.warning('Python {}'.format(_sys.version))

_LOG.error('{}: {}'.format(exc, self))
            warned = True
        elif isinstance(exc, _feedparser.zlib.error):
            _LOG.error('broken compression: {}'.format(self))
            warned = True
        elif isinstance(exc, (IOError, AttributeError)):
            _LOG.error('{}: {}'.format(exc, self))
            warned = True
        elif isinstance(exc, KeyboardInterrupt):
            raise exc
        elif isinstance(exc, _sax.SAXParseException):
            _LOG.error('sax parsing error: {}: {}'.format(exc, self))
            warned = True
        elif (parsed.bozo and
              isinstance(exc, _feedparser.CharacterEncodingOverride)):
            _LOG.warning(
                'incorrectly declared encoding: {}: {}'.format(exc, self))
            warned = True
        elif (parsed.bozo and isinstance(exc, _feedparser.NonXMLContentType)):
            _LOG.warning('non XML Content-Type: {}: {}'.format(exc, self))
            warned = True
        elif parsed.bozo or exc:
            if exc is None:
                exc = "can't process"
            _LOG.error('processing error: {}: {}'.format(exc, self))
            warned = True

        if (not warned and
            status in [200, 302] and
            not parsed.entries and
            not version):
            raise _error.ProcessingError(parsed=parsed, feed=self)

b'From: John '
    b'To: =?utf-8?b?zpbOtc+Nz4I=?= '
    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()

def log(self):
        super(NoToEmailAddress, self).log()
        _LOG.warning(
            "please run 'r2e email emailaddress' or "
            "'r2e add name url emailaddress'.")

def _check_for_errors(self, parsed):
        warned = False
        status = getattr(parsed, 'status', 200)
        _LOG.debug('HTTP status {}'.format(status))
        if status == 301:
            _LOG.info('redirect {} from {} to {}'.format(
                    self.name, self.url, parsed['url']))
            self.url = parsed['url']
        elif status not in [200, 302, 304, 307]:
            raise _error.HTTPError(status=status, feed=self)
        http_headers = parsed.get('headers', {})
        if http_headers:
            _LOG.debug('HTTP headers: {}'.format(http_headers))
        if not http_headers:
            _LOG.warning('could not get HTTP headers: {}'.format(self))
            warned = True
        else:
            if 'html' in http_headers.get('content-type', 'rss'):
                _LOG.warning('looks like HTML: {}'.format(self))
                warned = True
            if http_headers.get('content-length', '1') == '0':
                _LOG.warning('empty page: {}'.format(self))
                warned = True

        version = parsed.get('version', None)
        if version:
            _LOG.debug('feed version {}'.format(version))
        else:
            _LOG.debug('unrecognized version: {}'.format(self))
            warned = True

def log(self):
        super(SMTPConnectionError, self).log()
        _LOG.warning(
            'check your config file to confirm that smtp-server and other '
            'mail server settings are configured properly')
        if hasattr(self.__cause__, 'reason'):
            _LOG.error('reason: {}'.format(self.__cause__.reason))