func ExampleEqualFold() {
	fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
	// Output: true
}

func ExampleFields() {
	fmt.Printf("Fields are: %q", bytes.Fields([]byte("  foo bar  baz   ")))
	// Output: Fields are: ["foo" "bar" "baz"]
}

func ExampleFieldsFunc() {
	f := func(c rune) bool {
		return !unicode.IsLetter(c) && !unicode.IsNumber(c)
	}

	if err != nil {
		t.Fatalf("os.Stat: %v", err)
	}
	contents := strings.Repeat(" ", int(hdr.Size))

	hdr.Xattrs = map[string]string{
		"foo": "foo",
		"bar": "bar",
		"baz": "baz",
		"qux": "qux",
	}

	var buf bytes.Buffer
	writer := NewWriter(&buf)
	if err := writer.WriteHeader(hdr); err != nil {
		t.Fatal(err)
	}
	if _, err = writer.Write([]byte(contents)); err != nil {

		{string([]byte{0xff, 0xfe, 0xfd}), true},
		{`foo\bar`, true},
		{"Hello/世界", false},
	}

	for i, testCase := range testCases {
		err := ValidateFilterRuleValue(testCase.value)
		expectErr := (err != nil)

		header:  &Header{Xattrs: map[string]string{"用戶名": "\x00hello"}},
		paxHdrs: map[string]string{paxSchilyXattr + "用戶名": "\x00hello"},
		formats: FormatPAX,
	}, {
		header:  &Header{Xattrs: map[string]string{"foo=bar": "baz"}},
		formats: FormatUnknown,
	}, {
		header:  &Header{Xattrs: map[string]string{"foo": ""}},
		paxHdrs: map[string]string{paxSchilyXattr + "foo": ""},
		formats: FormatPAX,
	}, {