Multi-turn tool-use scenario.
Tools involved: MathAPI
TravelAPI

User requests (one per turn):
user: List all international airports currently accessible for travel.
user: I'm based in Crescent Hollow. Determine which airport is closest to my location from the previously listed options.
user: I'm organizing a trip soon and need the flight cost.
user: The flight is from my nearest airport to Pinehaven on March 3, 2024, traveling in business class

Expected function call sequence:
TravelAPI.list_all_airports
TravelAPI.get_nearest_airport_by_city
TravelAPI.get_flight_cost
MathAPI.mean