docs: def certain_kind_tap(data_items):
      """
      :param data_items: A sequence of unicode strings
      """
      fruit_spigot = Bucket(get_fruit)
      metal_spigot = Bucket(get_metal)
  
      items = stream_tap((fruit_spigot, metal_spigot), data_items)
  
      # consume iterator.
      for item in items:
          print item
  
      return fruit_spigot.contents(), metal_spigot.contents()