code: func (net *Network) ConnectNodesStar(ids []enode.ID, center enode.ID) (err error) {
  	net.lock.Lock()
  	defer net.lock.Unlock()
  
  	if ids == nil {
  		ids = net.getUpNodeIDs()
  	}
  	for _, id := range ids {
  		if center == id {
  			continue
  		}
  		if err := net.connectNotConnected(center, id); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // ConnectNodesStar connects all nodes into a star topology
  // If ids argument is nil, all nodes that are up will be connected.