code: func (nc *Conn) DiscoveredServers() []string {
  	nc.mu.RLock()
  	defer nc.mu.RUnlock()
  	return nc.getServers(true)
  }
docs: // DiscoveredServers returns only the server urls that have been discovered
  // after a connection has been established. If authentication is enabled,
  // use UserInfo or Token when connecting with these urls.