code: def add_item_to_sonos_playlist(self, queueable_item, sonos_playlist):
          
          # Get the update_id for the playlist
          response, _ = self.music_library._music_lib_search(
              sonos_playlist.item_id, 0, 1)
          update_id = response['UpdateID']
  
          # Form the metadata for queueable_item
          metadata = to_didl_string(queueable_item)
  
          # Make the request
          self.avTransport.AddURIToSavedQueue([
              ('InstanceID', 0),
              ('UpdateID', update_id),
              ('ObjectID', sonos_playlist.item_id),
              ('EnqueuedURI', queueable_item.resources[0].uri),
              ('EnqueuedURIMetaData', metadata),
              # 2 ** 32 - 1 = 4294967295, this field has always this value. Most
              # likely, playlist positions are represented as a 32 bit uint and
              # this is therefore the largest index possible. Asking to add at
              # this index therefore probably amounts to adding it "at the end"
              ('AddAtIndex', 4294967295)
          ])
docs: Adds a queueable item to a Sonos' playlist.
  
          Args:
              queueable_item (DidlObject): the item to add to the Sonos' playlist
              sonos_playlist (DidlPlaylistContainer): the Sonos' playlist to
                  which the item should be added