topic: models in UML and OCL

task 1: create model for "grocery store" (Tesco, Albert, Billa)
	- important entities to consider: goods (items, products), racks where the food and drinks are available to pick, warehouse (central, local), price list, orders, invoices, categories of goods, transport from the central warehouse to a local branch (store)
	- required: create an UML class diagram
	- optionally: create some other UML diagrams too (use case, sequence), if you really want
	- define some binary and ternary relations between classes (with reasonable multiplicities)
	- define some OCL constraints (derivation rules, invariants, pre-conditions and post-conditions)

task 2: document your solution
	- explain key design decisions (in plain text)

deadline: 14.1.2024