user_query: Add cellphone, power bank and headset to my Shopping list. 
response_text: Got it, I added cellphone, power bank and headset.
user_query: Remove headset from the list.
response_text: I couldn't find headset.
user_query: Remove headset from my Shopping list.
response_text: I couldn't find headset on your list called "Shopping."
User: put candy on my walmart list
Parse: Add_item_to_list ( items « candy » list_label « walmart » list_singular_or_plural « list » )