OrderBook Implementation Exercise

This project provides a base OrderBook class and a comprehensive test suite. Your task is to implement the OrderBook functionality by creating a class that inherits from the base OrderBook class.

Requirements

Your implementation should:

1. Complete the OrderBook class in orderbook.py
2. Implement all required methods:
   • submitOrder(order: Order) -> List[Trade]
   • cancelOrder(order_id: str) -> None
   • getPriceLevels() -> List[float]
   • getVolumeAtPrice(priceLevel: float) -> int

Order Handling Rules

• Orders with duplicate order_ids should be ignored (existing order should be preserved)
• Orders with zero or negative quantities should be ignored
• Orders with zero or negative prices should be ignored
• All valid prices must be positive float values

Testing Your Implementation

1. Create your implementation in orderbook.py
2. Run the tests using pytest: pytest test_orderbook.py