Design an OOD restaurant management system

## Object-oriented design: Restaurant management system Design an object-oriented system for a dine-in restaurant that supports the following: ### Functional requirements - The restaurant has **tables** with capacity; parties can be **seated** at a table. - A party can create **one or more orders**; an order contains multiple **order items** (menu item + quantity + special instructions). - The kitchen tracks order item **states** (e.g., `PLACED`, `IN_PREP`, `READY`, `SERVED`, `CANCELLED`). - The restaurant generates a **bill** for a table/party and supports **splitting the bill** (by item or by amount). - Payment can be made via multiple methods (cash/card); a bill can have multiple payments. ### Non-functional / design goals - Clean separation of concerns (table management, ordering, kitchen workflow, billing/payments). - Extensible to add features later (takeout/delivery, discounts, loyalty). ### What to provide - Key classes, fields, and methods (UML-style text is fine). - Important relationships (composition/aggregation) and patterns if appropriate. - Brief explanation of how typical flows work (seat → order → prepare → serve → bill → pay).