'Return an order with a specific id.'

def get_order(self, order_id):

    db_result = self.execute(u'SELECT    *    FROM    orders    WHERE    trader_id    =    ?    AND    order_number    =    ?', (unicode(order_id.trader_id), unicode(order_id.order_number))).fetchone()
    return (Order.from_database(db_result, self.get_reserved_ticks(order_id)) if db_result else None)
