code: func (p *Pool) pongKey() string {
  	p.RLock()
  	thisId := p.id
  	p.RUnlock()
  	return "workers:" + thisId + ":pong"
  }
docs: // pongKey is the key for a pub/sub connection which allows a pool to respond to
  // pings with a pong, i.e. acknowledge that it is still alive and working.