Receive changes of TracklistController.index

I would like to be notified about any change of the current index in the track list. Unfortunately, there is no such signal in the current API (or am I wrong?)

Instead, every time I expect the index to be changed, e.g. after calling methods, I call TracklistController.index() without any parameters, which causes Mopidy to have index sent back.

Unfortunately, since operations are asynchronous, I often receive index before Mopidy starts play() operation and changes this index.

Is there an easy way around this? Perhaps a “secret” way to subscribe to any changes in the current index?

Thank you.