code: function infoId(queue, info) {
    for (var i = 0, length = queue.length, tmp; i < length; i++) {
      tmp = queue[i];
      if (
        tmp.fn === info.fn &&
        sameValues(tmp.ar, info.ar)
      ) return tmp.id;
    }
    return null;
  }
docs: return a scheduled unique id through similar info