How to use the rss2email.error.DataFileError function in rss2email

def __init__(self, feeds=None, message=None, **kwargs):
        if message is None:
            message = 'error with feeds'
        super(FeedsError, self).__init__(message=message, **kwargs)
        self.feeds = feeds


class DataFileError (FeedsError):
    def __init__(self, feeds, message=None):
        if message is None:
            message = 'problem with the feed data file {}'.format(
                feeds.datafile)
        super(DataFileError, self).__init__(feeds=feeds, message=message)


class NoDataFile (DataFileError):
    def __init__(self, feeds):
        message = 'feed data file {} does not exist'.format(feeds.datafile)
        super(NoDataFile, self).__init__(feeds=feeds, message=message)

    def log(self):
        super(NoDataFile, self).log()
        _LOG.warning(
            "if you're using r2e for the first time, you have to run "
            "'r2e new' first.")


class NoToEmailAddress (InvalidFeedConfig, FeedsError):
    def __init__(self, feed, **kwargs):
        message = 'no target email address has been defined'
        super(NoToEmailAddress, self).__init__(
            setting='to', feed=feed, message=message, **kwargs)

level = _LOG.level
        handlers = list(_LOG.handlers)
        feeds = []
        try:
            data = _json.load(self._datafile_lock)
        except ValueError as e:
            _LOG.info('could not load data file using JSON')
            data = self._load_pickled_data(self._datafile_lock)
        version = data.get('version', None)
        if version != self.datafile_version:
            data = self._upgrade_state_data(data)
        for state in data['feeds']:
            feed = _feed.Feed(name='dummy-name')
            feed.set_state(state)
            if 'name' not in state:
                raise _error.DataFileError(
                    feeds=self,
                    message='missing feed name in datafile {}'.format(
                        self.datafile))
            feeds.append(feed)
        _LOG.setLevel(level)
        _LOG.handlers = handlers
        self.extend(feeds)

        if locktype == 0:
            self._datafile_lock.close()
            self._datafile_lock = None

        for feed in self:
            feed.load_from_config(self.config)

        feed_names = set(feed.name for feed in self)

def __init__(self, feeds, message=None):
        if message is None:
            message = 'problem with the feed data file {}'.format(
                feeds.datafile)
        super(DataFileError, self).__init__(feeds=feeds, message=message)

_LOG.debug('load feed data from {}'.format(self.datafile))
        if not _os.path.exists(self.datafile):
            if require:
                raise _error.NoDataFile(feeds=self)
            _LOG.info('feed data file not found at {}'.format(self.datafile))
            _LOG.debug('creating an empty data file')
            dirname = _os.path.dirname(self.datafile)
            if dirname and not _os.path.isdir(dirname):
                _os.makedirs(dirname, mode=0o700, exist_ok=True)
            with _codecs.open(self.datafile, 'w', self.datafile_encoding) as f:
                self._save_feed_states(feeds=[], stream=f)
        try:
            self._datafile_lock = _codecs.open(
                self.datafile, 'r', self.datafile_encoding)
        except IOError as e:
            raise _error.DataFileError(feeds=self) from e

        locktype = 0
        if lock and UNIX:
            locktype = _fcntl.LOCK_SH
            _fcntl.lockf(self._datafile_lock.fileno(), locktype)

        self.clear()

        level = _LOG.level
        handlers = list(_LOG.handlers)
        feeds = []
        try:
            data = _json.load(self._datafile_lock)
        except ValueError as e:
            _LOG.info('could not load data file using JSON')
            data = self._load_pickled_data(self._datafile_lock)