Multi-turn user requests:
user: I plan to book a flight from Crescent Hollow to New York, aimed at a business endeavor. Utilize my typical credit card (ID=card_6789) and access token 'abc123xyz' for the payment. Schedule it for economy class on November 12th 2024, making sure my frequent flyer discount is applied, ensuring the total fee is $850.
user: Post-booking, pondering added precautions, getting travel insurance seems wise, aiming for a 100 insurance. Proceed with organizing this with identical travel specifics, and the previously mentioned credit card should facilitate payment.
user: For clarity on financial allocations, I need to gather the invoice that details my recently acquired flight and insurance.
user: Given sudden itinerary conflicts, there's a pivot. Inform customer support of my potential adjustments or explore full refund possibilities because of a family emergency.

Involved API classes: TravelAPI

Initial environment state:
TravelAPI: credit_card_list: card_6789: card_number: 4938 5639 9827 6789
cardholder_name: Ethan Hawke
expiry_date: 12/25
cvv: 123
balance: 17890
access_token: abc123xyz
token_type: Bearer
token_expires_in: 3600
token_scope: read write
user_first_name: Ethan
user_last_name: Hawke
budget_limit: 2000

Ground-truth function call path:
TravelAPI.get_nearest_airport_by_city
TravelAPI.book_flight
TravelAPI.purchase_insurance
TravelAPI.retrieve_invoice
TravelAPI.contact_customer_support
TravelAPI.cancel_booking

Functions held out until the model asks (by turn index):
3: retrieve_invoice