code: function unsubscribe(channel, cb) {
        db.unsubscribe(channel,function(err){
          delete subscriptionCbs[channel];
          return cb(err);
        });
      }
docs: Note that this will remove ANY existing subscription on this channel. If another request has made a subsequent subscription to this channel, this unsubscribe will remove it. Once again, for our purposes, this is okay (if another request comes in for the same UUID and gets unsubscribed by the first one timing out, that's the edge case coming back to bite you), but in another circumstance you would probably want a more robust solution.