Pisiniiffik datastruktuurinik nikalernerani kingorna ilisarnitsiuvoq
Piareersarfik ilinniarfik inissornermi pitsaasut taalliat. 

Product ilisarnertainik piffissami kingorna: 
    - name 
    - price 
    - barcode 
    - quantity

Item ilisarnertainik, Product-imi tammaani kingorna: 
    - name 
    - price 
    - barcode 
    - quantity 
    - weight

Cart ilisarnertainik piffissami kingorna: 
    - items 

    - add_item 
    - remove_item 
    - get_total_price

Checkout ilisarnertainik piffissami kingorna: 
    - cart 

    - scan_item 
    - remove_item 
    - get_total 
    - pay