Multi-turn user requests:
user: Hello, I've just come upon a remarkable opportunity to explore some new places, and it's crucial that my documents are up-to-date before I depart. Would you be able to verify my personal details? I'm [Redacted], with a birth date of 1995-08-15, and my passport number is 'US1234'.
user: Wonderful news has reached me—it turns out everything is verified accurately! Now, to facilitate a smooth departure, I must quickly locate the nearest airport.
user: The city you're looking for is San Francisco, departing from LAX.
user: Having affirmed the specifics of my journey, I'm now curious to determine the cost of a first-class flight on December 15th 2024 from LAX to the San Francisco airport.
user: Splendid, all arrangements are in place! Might you finalize the booking for my flight on December 15th utilizing my funds available through card ID 'card_9012'? I'm equipped with my authorization token 'auth_token_987654321' for any verification needed.
user: Alas, circumstances have altered! I urgently need to reverse the reservation I just completed. Please apply the same authorization token to manage the cancellation.

Ground-truth function call sequence:
TravelAPI.verify_traveler_information
TravelAPI.get_nearest_airport_by_city
TravelAPI.get_flight_cost
TravelAPI.book_flight
TravelAPI.cancel_booking