def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def get(self, section, option):
            if _section == section:
                if option == 'memcache_servers':
                    if _srvs == 'error':
                        raise NoOptionError(option, section)
                    return _srvs
                elif option == 'memcache_serialization_support':
                    if _sers == 'error':
                        raise NoOptionError(option, section)
                    return _sers
                elif option in ('memcache_max_connections',
                                'max_connections'):
                    if _maxc == 'error':
                        raise NoOptionError(option, section)
                    return _maxc
                else:
                    raise NoOptionError(option, section)
            else:
                raise NoSectionError(option)