code: def add(self, itm, **options):
          
          if not options:
              options = None
          self._d[itm] = options
docs: Convenience method to add an item together with a series of options.
  
          :param itm: The item to add
          :param options: keyword arguments which will be placed in the item's
              option entry.
  
          If the item already exists, it (and its options) will be overidden. Use
          :attr:`dict` instead to update options