Warm up exercise introduce domain concept in small steps

In the VendingMachine there are two HashMaps of choice to something

• choice to price
• choice to can (type)

It seems that there is a concept missing that combines the price and can. It could be something like:

• Dispenser / Drawer / Shelf (some concept that holds one type of cans and is able to dispense one)
• Product (some concept that holds the type of product and the price)

Try to introduce a concept like that by changing one line at a time as much as possible.

I.e. DO NOT introduce a class and try to integrate it in one big integration step.