code: func (net *Network) ConnectNodesChain(ids []enode.ID) (err error) {
  	net.lock.Lock()
  	defer net.lock.Unlock()
  
  	return net.connectNodesChain(ids)
  }
docs: // ConnectNodesChain connects all nodes in a chain topology.
  // If ids argument is nil, all nodes that are up will be connected.