user_query: Create a shopping list: orange, apples, cucumber.
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: Creat a grocery list.
response_text: Got it, I made a list called "Grocery List".
user_query: Add to grocery list: apples, oranges, cucumber
response_text: Got it, I added those two things.
User: add cereal and bread to new grocery list
Parse: Create_list ( items « grocery » items « cereal » items « bread » )