code: func onListClusters(cf *CLIConf) {
  	tc, err := makeClient(cf, true)
  	if err != nil {
  		utils.FatalError(err)
  	}
  	proxyClient, err := tc.ConnectToProxy(cf.Context)
  	if err != nil {
  		utils.FatalError(err)
  	}
  	defer proxyClient.Close()
  
  	var sites []services.Site
  	err = client.RetryWithRelogin(cf.Context, tc, func() error {
  		sites, err = proxyClient.GetSites()
  		return err
  	})
  	if err != nil {
  		utils.FatalError(err)
  	}
  	var t asciitable.Table
  	if cf.Quiet {
  		t = asciitable.MakeHeadlessTable(2)
  	} else {
  		t = asciitable.MakeTable([]string{"Cluster Name", "Status"})
  	}
  	if len(sites) == 0 {
  		return
  	}
  	for _, site := range sites {
  		t.AddRow([]string{site.Name, site.Status})
  	}
  	fmt.Println(t.AsBuffer().String())
  }
docs: // onListClusters executes 'tsh clusters' command