// returning nil instead of empty slice if all spaces.
		return nil
	}
	return s[start:stop]
}

// Runes interprets s as a sequence of UTF-8-encoded code points.
// It returns a slice of runes (Unicode code points) equivalent to s.
func Runes(s []byte) []rune {
	t := make([]rune, utf8.RuneCount(s))
	i := 0
	for len(s) > 0 {
		r, l := utf8.DecodeRune(s)
		t[i] = r
		i++
		s = s[l:]
	}

		Short: "Open Prometheus web UI",
		Long:  `Open Istio's Prometheus dashboard`,
		Example: `  istioctl dashboard prometheus

  # with short syntax
  istioctl dash prometheus
  istioctl d prometheus`,
		RunE: func(cmd *cobra.Command, args []string) error {
			client, err := ctx.CLIClientWithRevision(opts.Revision)
			if err != nil {
				return fmt.Errorf("failed to create k8s client: %v", err)
			}

// UTF-8-encoded rune as a token. The sequence of runes returned is
// equivalent to that from a range loop over the input as a string, which
// means that erroneous UTF-8 encodings translate to U+FFFD = "\xef\xbf\xbd".
// Because of the Scan interface, this makes it impossible for the client to
// distinguish correctly encoded replacement runes from encoding errors.

// converted to int they correspond to the rune size that was read.
type readOp int8

// Don't use iota for these, as the values need to correspond with the
// names and comments, which is easier to see when being explicit.
const (
	opRead      readOp = -1 // Any other read operation.
	opInvalid   readOp = 0  // Non-read operation.
	opReadRune1 readOp = 1  // Read rune of size 1.
	opReadRune2 readOp = 2  // Read rune of size 2.

	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsNumber))
	// Output:
	// 8
	// 9
	// -1
}

func ExampleMap() {
	rot13 := func(r rune) rune {
		switch {
		case r >= 'A' && r <= 'Z':
			return 'A' + (r-'A'+13)%26
		case r >= 'a' && r <= 'z':
			return 'a' + (r-'a'+13)%26
		}
		return r
	}

// a canonical form. Practically this means that we convert any punctuation to
// dashes, which is how the UID is represented within Kubernetes.
func canonicalizePodUID(uid string) types.UID {
	return types.UID(strings.Map(func(r rune) rune {
		if unicode.IsPunct(r) {
			r = '-'
		}
		return r
	}, uid))
}

// Cgroup represents a linux cgroup.
type Cgroup struct {
	HierarchyID    string
	ControllerList string

  		 istioctl waypoint status --namespace default`,
		Args: func(cmd *cobra.Command, args []string) error {
			if len(args) != 0 {
				return fmt.Errorf("unknown subcommand %q", args[0])
			}
			return nil
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			kubeClient, err := ctx.CLIClient()
			if err != nil {
				return fmt.Errorf("failed to create Kubernetes client: %v", err)
			}

  istioctl ztunnel-config certificates <ztunnel-name[.namespace]> -o json
`,
		Aliases: []string{"certificates", "certs", "cert"},
		Args:    common.validateArgs,
		RunE: runConfigDump(ctx, common, func(cw *ztunnelDump.ConfigWriter) error {
			switch common.outputFormat {
			case summaryOutput:
				return cw.PrintSecretSummary()
			case jsonOutput, yamlOutput:

	b.lastRuneSize = -1
	return nil
}

// ReadRune reads a single UTF-8 encoded Unicode character and returns the
// rune and its size in bytes. If the encoded rune is invalid, it consumes one byte
// and returns unicode.ReplacementChar (U+FFFD) with a size of 1.
func (b *Reader) ReadRune() (r rune, size int, err error) {
	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil && b.w-b.r < len(b.buf) {

	//
	//	R1
	//	offset
	//	$offset
	// Every piece is optional, so we scan left to right and what
	// we discover tells us where we are.

	// Prefix: $.
	var prefix rune
	switch tok := p.peek(); tok {
	case '$', '*':
		prefix = rune(tok)
		p.next()
	}

	// Symbol: sym±offset(SB)
	tok := p.next()
	name := tok.String()
	if tok.ScanToken == scanner.Ident && !p.atStartOfRegister(name) {