private void OnOrderRemoved(Order order)
 {
     if (order.Type == OrderType.BUY)
     {
         BuyingOrders.Remove(order);
         RaisePropertyChanged(() => BuyingOrders);
     }
     else
     {
         SellingOrders.Remove(order);
         RaisePropertyChanged(() => SellingOrders);
     }
 }
 private void OnNewOrderAdded(Order order)
 {
     if (order.Type == OrderType.BUY)
     {
         BuyingOrders = new ObservableCollection <Order>(BuyingOrders.Where(x => x.Id != order.Id).ToList());
         BuyingOrders.Add(order);
         RaisePropertyChanged(() => BuyingOrders);
     }
     else
     {
         SellingOrders = new ObservableCollection <Order>(SellingOrders.Where(x => x.Id != order.Id).ToList());
         SellingOrders.Add(order);
         RaisePropertyChanged(() => SellingOrders);
     }
 }