Added some comments.

wobuzz/player/track.py

@@ -33,6 +33,7 @@ class Track:
         new_occurrences = {}
 
         for item in self.items:
+            # create dict of item: item.index (actually the id of the item bc. the item can't be used as key)
             playlist_occurrences = new_occurrences.get(item.playlist, {})
             playlist_occurrences[id(item)] = item.index