'Consume variables and sort order for ORDER BY clause.'

def __OrderList(self):

    identifier = self.__Identifier()
    if identifier:
        if self.__Accept('DESC'):
            self.__orderings.append((identifier, datastore.Query.DESCENDING))
        elif self.__Accept('ASC'):
            self.__orderings.append((identifier, datastore.Query.ASCENDING))
        else:
            self.__orderings.append((identifier, datastore.Query.ASCENDING))
    else:
        self.__Error('Invalid    ORDER    BY    Property')
    logging.log(LOG_LEVEL, self.__orderings)
    if self.__Accept(','):
        return self.__OrderList()
    return self.__Limit()
