public Output addOrder(Order ord)
        {
            LLNode order = new LLNode(ord);
            _orderIDLkp.Add(ord.OrderID, ord);
            OrdersLinkedList relevantList = ord.IsBuy ? _buyLinkedList : _sellLinkedList;

            relevantList.insert(order);
            return isChanged(ord.IsBuy, ord);
        }
 public void insert(LLNode newNode)
 {
     if (_head == null || _head.Value.CompareTo(newNode.Value) > 0)
     {
         newNode.Next = _head;
         _head = newNode;
     }
     else
     {
         LLNode current = _head;
         while (current.Next != null && current.Next.Value.CompareTo(newNode.Value) < 0)
         {
             current = current.Next;
         }
         newNode.Next = current.Next;
         current.Next = newNode;
     }
 }
        public void remove(Order orderToRemove)
        {
            if (_head == null) throw new InvalidOperationException("Cannot remove orders when there are no orders");

            if (_head.Value.Equals(orderToRemove))
            {
                LLNode current = _head;
                _head = _head.Next;
                current.Value = null;
                current.Next = null;
                //current = null;
            }
            else
            {
                LLNode current = _head;
                while (current.Next != null && current.Next.Value.Equals(orderToRemove) == false)
                {
                    current = current.Next;
                }

                if (current.Next == null) throw new Exception("Order to remove not found in OrderBook");

                //set previous nodes next to deleted nodes next
                LLNode nodeToDelete = current.Next;
                current.Next = nodeToDelete.Next;// current.Next.Next;

                nodeToDelete.Next = null;
                nodeToDelete.Value = null;
                nodeToDelete = null;
            }
        }