def find_or_create_by_name(self, item_name, items_list, item_type):
        """
        See if item with item_name exists in item_list.
        If not, create that item.
        Either way, return an item of type item_type.
        """
        item = self.find_by_name(item_name, items_list)
        if not item:
            item = self.data_lists[item_type][2](item_name, None)
        return item
See if item with item_name exists in item_list.
        If not, create that item.
        Either way, return an item of type item_type.