Multi-turn user requests:
user: I'm planning a journey from Los Angeles to New York on the morning of April 15th 2024, preferring to fly business class. However, my funds are in Euros. Arrange this flight using my pre-linked credit card with id 'card_123456789' and access token 'abc123xyz'.
user: With my flight now secured, I need to review the invoice outlining the costs involved. Retrieve that invoice for me, please.
user: There were hiccups during the booking process. Reach out to customer support and detail the challenges I faced.
user: Once you've reached out to them, please brief my colleague on the situation using my sender id.
user: The colleague's id is 'Kevin1048'.
user: Finally, compile and present all the responses received following the communications regarding the flight issue.

Tools involved: MessageAPI
TravelAPI
Expected function-call sequence: TravelAPI.compute_exchange_rate
TravelAPI.get_flight_cost
TravelAPI.book_flight
TravelAPI.retrieve_invoice
TravelAPI.contact_customer_support
MessageAPI.send_message
MessageAPI.view_messages_received