public OperationResult Create(CreateInventory command) { var operationResult = new OperationResult(); if (_inventoryRepo.Exists(c => c.ProductId == command.ProductId)) { return(operationResult.Failed(ApplicationMessage.duplicated)); } var inventory = new Inventory(command.ProductId, command.UnitPrice); _inventoryRepo.Create(inventory); _inventoryRepo.Save(); return(operationResult.Succeeded()); }