code: func (cli *NetworkCli) CmdNetwork(chain string, args ...string) error {
  	cmd := cli.Subcmd(chain, "network", "COMMAND [OPTIONS] [arg...]", networkUsage(chain), false)
  	cmd.Require(flag.Min, 1)
  	err := cmd.ParseFlags(args, true)
  	if err == nil {
  		cmd.Usage()
  		return fmt.Errorf("invalid command : %v", args)
  	}
  	return err
  }
docs: // CmdNetwork handles the root Network UI