user_query: Could you create a list for me named Costco
response_text: Sorry, it looks like you already have a list with that name. Do you still want to make a new one?
user_query: Add pears and bananas
response_text: Got it, what do you want to call it?
user_query: paper plates and plastic utensils
response_text: Sorry, I didn't get that. What do you want to call that list?
user_query: frozen berries
response_text: OK, I made a list called "Frozen Berries" and added those two things.
User: ask TicketHub to buy tickets to see Mary Poppins, no Rocky Horror
Parse: BuyEventTickets ( event_performer « Rocky Horror » provider « TicketHub » )