wantJSON: `{"g":{"n":4,"h":{"i":{"c":3}}}}`,
		},
		{
			name: "replace partial empty attrs 3",
			with: func(h Handler) Handler {
				return h.WithGroup("g").WithAttrs([]Attr{Int("x", 0)}).WithAttrs([]Attr{Int("a", 1)}).WithAttrs([]Attr{Int("n", 4)}).WithGroup("h").WithAttrs([]Attr{Int("b", 2)})
			},
			replace: func(groups []string, attr Attr) Attr {
				return removeKeys(TimeKey, LevelKey, MessageKey, "a", "c")(groups, attr)
			},

		},
	},
	{
		name:        "resolve-WithAttrs",
		explanation: withSource("a Handler should call Resolve on attribute values from WithAttrs"),
		f: func(l *slog.Logger) {
			l = l.With("k", &replace{"replaced"})
			l.Info("msg")
		},
		checks: []check{hasAttr("k", "replaced")},
	},
	{
		name:        "resolve-WithAttrs-groups",

func (h *LevelHandler) Handle(ctx context.Context, r slog.Record) error {
	return h.handler.Handle(ctx, r)
}

// WithAttrs implements Handler.WithAttrs.
func (h *LevelHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
	return NewLevelHandler(h.level, h.handler.WithAttrs(attrs))
}

// WithGroup implements Handler.WithGroup.
func (h *LevelHandler) WithGroup(name string) slog.Handler {

		panic(fmt.Sprintf("bad kind: %s", v.Kind()))
	}
}

func (h *fastTextHandler) appendTime(buf *buffer.Buffer, t time.Time) {
	*buf = strconv.AppendInt(*buf, t.Unix(), 10)
}

func (h *fastTextHandler) WithAttrs([]slog.Attr) slog.Handler {
	panic("fastTextHandler: With unimplemented")
}

func (*fastTextHandler) WithGroup(string) slog.Handler {
	panic("fastTextHandler: WithGroup unimplemented")
}

func (h *TextHandler) Enabled(_ context.Context, level Level) bool {
	return h.commonHandler.enabled(level)
}

// WithAttrs returns a new [TextHandler] whose attributes consists
// of h's attributes followed by attrs.
func (h *TextHandler) WithAttrs(attrs []Attr) Handler {
	return &TextHandler{commonHandler: h.commonHandler.withAttrs(attrs)}
}

func (h *TextHandler) WithGroup(name string) Handler {

func (h *JSONHandler) Enabled(_ context.Context, level Level) bool {
	return h.commonHandler.enabled(level)
}

// WithAttrs returns a new [JSONHandler] whose attributes consists
// of h's attributes followed by attrs.
func (h *JSONHandler) WithAttrs(attrs []Attr) Handler {
	return &JSONHandler{commonHandler: h.commonHandler.withAttrs(attrs)}
}

func (h *JSONHandler) WithGroup(name string) Handler {

	//   - If a group has no Attrs (even if it has a non-empty key),
	//     ignore it.
	Handle(context.Context, Record) error

	// WithAttrs returns a new Handler whose attributes consist of
	// both the receiver's attributes and the arguments.
	// The Handler owns the slice: it may retain, modify or discard it.
	WithAttrs(attrs []Attr) Handler

	// WithGroup returns a new Handler with the given group appended to
	// the receiver's existing groups.

	return h.h.Enabled(ctx, level)
}
func (h wrappingHandler) WithGroup(name string) Handler              { return h.h.WithGroup(name) }
func (h wrappingHandler) WithAttrs(as []Attr) Handler                { return h.h.WithAttrs(as) }
func (h wrappingHandler) Handle(ctx context.Context, r Record) error { return h.h.Handle(ctx, r) }

func TestAttrs(t *testing.T) {
	check := func(got []Attr, want ...Attr) {

	}
	return []byte(fmt.Sprintf("text{%q}", t.s)), nil
}

func TestTextHandlerPreformatted(t *testing.T) {
	var buf bytes.Buffer
	var h Handler = NewTextHandler(&buf, nil)
	h = h.WithAttrs([]Attr{Duration("dur", time.Minute), Bool("b", true)})
	// Also test omitting time.
	r := NewRecord(time.Time{}, 0 /* 0 Level is INFO */, "m", 0)
	r.AddAttrs(Int("a", 1))

pkg log/slog, type Handler interface, Enabled(context.Context, Level) bool #56345
pkg log/slog, type Handler interface { Enabled, Handle, WithAttrs, WithGroup } #56345
pkg log/slog, type Handler interface, Handle(context.Context, Record) error #56345
pkg log/slog, type Handler interface, WithAttrs([]Attr) Handler #56345
pkg log/slog, type Handler interface, WithGroup(string) Handler #56345
pkg log/slog, type HandlerOptions struct #56345