public DisplayOrderLine(OrderLineDTO orderLineDTO, DisplayOrder order)
 {
     _order     = order;
     Amount     = orderLineDTO.Amount;
     Consumable = new Consumable(orderLineDTO.ConsumableDTO);
 }
 public DisplayOrderLine(int amount, Consumable consumable, DisplayOrder order)
 {
     _order     = order;
     Amount     = amount;
     Consumable = consumable;
 }