Multi-turn user requests:
user: As I'm in the process of planning an upcoming journey, I have specific departure and arrival cities in mind. Could you assist in estimating the airfare between two cities from the comprehensive list available through the system? Please note, I am considering traveling next weekend with a preference for a business class seat.
user: The cities are ORD and SVP, and the travel date is July 14th, 2024.
user: In pursuit of a cost-effective travel experience, I seek your guidance to manage my expenditure effectively. Could you help establish a budget limit of 20,000 RMB using my currently active account? The access token is 'abc123xyz456'.

Tools involved: TravelAPI
Expected function-call sequence: TravelAPI.list_all_airports
TravelAPI.get_flight_cost
TravelAPI.compute_exchange_rate
TravelAPI.set_budget_limit