code: func (m *Streamer) Stop(streamID StreamID) {
  	strm, ok := m.loadStream(streamID)
  	if !ok {
  		return
  	}
  
  	close(strm.done)
  
  	go func() {
  		// wait some time to ensure clients have connected, once they've
  		// retrieved the stream from the map it's safe to delete the key
  		time.Sleep(m.graceTime)
  
  		m.streams.Delete(streamID)
  	}()
  }
docs: // Stop stops streaming from the specified pair of channels.