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)
	}

func TestIndexRune(t *testing.T) {
	tests := []struct {
		in   string
		rune rune
		want int
	}{
		{"", 'a', -1},
		{"", '☺', -1},
		{"foo", '☹', -1},
		{"foo", 'o', 1},
		{"foo☺bar", '☺', 3},
		{"foo☺☻☹bar", '☹', 9},
		{"a A x", 'A', 2},
		{"some_text=some_value", '=', 9},
		{"☺a", 'a', 3},
		{"a☻☺b", '☺', 4},

		// RuneError should match any invalid UTF-8 byte sequence.
		{"�", '�', 0},

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

	if !bytes.Contains(buf.Bytes(), []byte("PaxHeaders.0")) {
		t.Fatal("Expected at least one PAX header to be written.")
	}

	// xattr bar should always appear before others
	indices := []int{
		bytes.Index(buf.Bytes(), []byte("bar=bar")),
		bytes.Index(buf.Bytes(), []byte("baz=baz")),
		bytes.Index(buf.Bytes(), []byte("foo=foo")),
		bytes.Index(buf.Bytes(), []byte("qux=qux")),
	}