public CartridgeService(ICartridgeRepository iRepository, ICartridgeCostRepository iCostRepository, ICartridgeQuantityRepository iQuantityRepository)
 {
     this.repository         = iRepository;
     this.costRepository     = iCostRepository;
     this.quantityRepository = iQuantityRepository;
 }
 public CartridgeService()
 {
     this.repository         = new CartridgeRepository();
     this.costRepository     = new CartridgeCostRepository();
     this.quantityRepository = new CartridgeQuantityRepository();
 }