code: func (h *handler) Stop() {
  	// Lock the mutex.
  	h.mutex.Lock()
  	defer h.mutex.Unlock()
  
  	// Signal the stop request by closing the channel if open.
  	if !h.stopChanClosed {
  		close(h.stopChan)
  		h.stopChanClosed = true
  	}
  }
docs: // Stop the handler if present.