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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _save_file_and_pos(self):
 """ Save current position into file """

        if not self._pos_changed:
            return
        with open(self.pos_storage_filename, 'w+') as f:
            _pos = '%s:%s' % (self._log_file, self._log_pos)
            _logger.debug('Saving position %s to file %s'
                          % (_pos, self.pos_storage_filename))
            f.write(_pos)
            self._pos_changed = False