If I try to add a track to the play queue, it will silently not be appended if it is also listed earlier in the queue: i.e. duplicates are forbidden.

This restriction makes sense in playlists, but not in the queue: if I want to listen to the same song 3 times in a row, why should RB stop me? More reasonably/realistically, sometimes I have a long queue and there's a song I like enough that I want to hear it twice (with others in-between).

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