def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def execute_as(self, user):
        self.check_prereq(self.LOGGED_IN)
        self._exit_modes_beyond(self.LOGGED_IN)
        user.commandLine(self)
        user.login()
        self.modeList.append(user)
        return user