Requirements

Assign parking spots based on vehicle size, allowing motorcycles to park in small spots, cars in medium spots, and trucks in large spots, with the option to park in larger spots if needed.
Issue a ParkingTicket upon vehicle entry, which records the vehicle information, assigned parking spot, and entry timestamp.
Compute the parking fee upon vehicle exit based on the duration of stay and a configurable pricing strategy.
Handle scenarios where the parking lot is full by rejecting entry and displaying a lot-full indicator to the driver.
Support multiple floors in the parking lot, with each floor containing a mix of small, medium, and large parking spots.

List the key non-functional requirements (eg thread safety, extensibility, maintainability, etc.)...