public string DisplayOrderBook(string name)
        {
            Orders.OrderBook    orderBook  = OrderBookCollection.getInstrument(name);
            OrderBookAggregator aggregator = new OrderBookAggregator(orderBook);

            return(aggregator.AggregateAndDisplay());
        }
        public string BookLimitOrder(string name, int side, int size, int price, string trader)
        {
            Orders.OrderBook orderBook   = OrderBookCollection.getInstrument(name);
            BookingUnit      bookingUnit = new BookingUnit(orderBook);

            return(bookingUnit.LimitOrder(side, size, price, trader));
        }