func (c *Comparator) ClusterDiff() error {
	envoyBytes, istiodBytes := &bytes.Buffer{}, &bytes.Buffer{}
	envoyClusterDump, err := c.envoy.GetDynamicClusterDump(true)
	if err != nil {
		envoyBytes.WriteString(err.Error())
	} else {
		envoy, err := protomarshal.ToJSONWithAnyResolver(envoyClusterDump, "    ", &envoyResolver)
		if err != nil {
			return err
		}
		envoyBytes.WriteString(envoy)
	}

		return err
	}
	if outputFormat == "yaml" {
		if out, err = yaml.JSONToYAML(out); err != nil {
			return err
		}
	}
	_, _ = fmt.Fprintln(c.Stdout, string(out))
	return nil
}

func (c *ConfigWriter) setupClusterConfigWriter() (*tabwriter.Writer, []*cluster.Cluster, error) {
	clusters, err := c.retrieveSortedClusterSlice()
	if err != nil {
		return nil, nil, err
	}

func (w *Wrapper) GetClusterConfigDump() (*admin.ClustersConfigDump, error) {
	clusterDumpAny, err := w.getSection(clusters)
	if err != nil {
		return nil, err
	}
	clusterDump := &admin.ClustersConfigDump{}
	err = clusterDumpAny.UnmarshalTo(clusterDump)
	if err != nil {
		return nil, err
	}
	return clusterDump, nil

// (see https://docs.google.com/document/d/1F__vEKeI41P7PPUCMM9PVPYY34pyrvQI5rbTJVnS5c4)
func clusterUID(client kubernetes.Interface) (types.UID, error) {
	kubeSystem, err := client.CoreV1().Namespaces().Get(context.TODO(), "kube-system", metav1.GetOptions{})
	if err != nil {
		return "", err
	}
	return kubeSystem.UID, nil