code: func (q *UniqueQueue) Clear() {
  	q.lock.Lock()
  	defer q.lock.Unlock()
  	if q.queue.Len() > 0 {
  		q.queue = make(TimedQueue, 0)
  	}
  	if len(q.set) > 0 {
  		q.set = sets.NewString()
  	}
  }
docs: // Clear removes all items from the queue and duplication preventing
  // set.