Encapsulated in IProductService
Switch to IProductService interface
Added Tests for MWVM
Refactored AddTransactionItem
Qty defaults to 1
Added Testing Suite for MWVM
addSaleStuff

Added Sale, SaleDTO, SaleRepository interface, and SaleService classes
addedServiceInterfaces

Interfaces added for service class, interface folder structure changed
slightly, namespaces adjusted
Encapsulated in IProductService
Switched to db team IProductService
Forgot to save changes to ProductService
Merging MWVM-Improvements
Made ISaleRepository public