'Update timestamp for given URL.'

def put_timestamp(self, url, timestamp):

    self._fetch_data()
    with self._lock:
        with open(self._data_file, 'wb') as myfile:
            self._data.update({url: timestamp})
            _LOGGER.debug('Overwriting    feed    %s    timestamp    in    storage    file    %s', url, self._data_file)
            try:
                pickle.dump(self._data, myfile)
            except:
                _LOGGER.error('Error    saving    pickled    data    to    %s', self._data_file)
    self._cache_outdated = True
