code: def add_item(self, title, key, synonyms=None, description=None, img_url=None):
          
          item = build_item(title, key, synonyms, description, img_url)
          self._items.append(item)
          return self
docs: Adds item to a list or carousel card.
  
          A list must contain at least 2 items, each requiring a title and object key.
  
          Arguments:
              title {str} -- Name of the item object
              key {str} -- Key refering to the item.
                          This string will be used to send a query to your app if selected
  
          Keyword Arguments:
              synonyms {list} -- Words and phrases the user may send to select the item
                                (default: {None})
              description {str} -- A description of the item (default: {None})
              img_url {str} -- URL of the image to represent the item (default: {None})