http:           &http.Client{},
				registry:       TestingRegistry(t),
			}
			req := &http.Request{}
			server.handleStats(rec, req)
			if rec.Code != 200 {
				t.Fatalf("handleStats() => %v; want 200", rec.Code)
			}
			if !strings.Contains(rec.Body.String(), tt.output) {
				t.Fatalf("handleStats() => %v; want %v", rec.Body.String(), tt.output)
			}

			parser := expfmt.TextParser{}

	// Add the handler for ready probes.
	mux.HandleFunc(readyPath, s.handleReadyProbe)
	// Default path for prom
	mux.HandleFunc(`/metrics`, s.handleStats)
	// Envoy uses something else - and original agent used the same.
	// Keep for backward compat with configs.
	mux.HandleFunc(`/stats/prometheus`, s.handleStats)
	mux.HandleFunc(quitPath, s.handleQuit)
	mux.HandleFunc(drainPath, s.handleDrain)
	mux.HandleFunc("/app-health/", s.handleAppProbe)

	s := handleState{
		h:       h,
		buf:     buf,
		freeBuf: freeBuf,
		sep:     sep,
		prefix:  buffer.New(),
	}
	if h.opts.ReplaceAttr != nil {
		s.groups = groupPool.Get().(*[]string)
		*s.groups = append(*s.groups, h.groups[:h.nOpenGroups]...)
	}
	return s
}

func (s *handleState) free() {
	if s.freeBuf {
		s.buf.Free()
	}

func (h *JSONHandler) Handle(_ context.Context, r Record) error {
	return h.commonHandler.handle(r)
}

// Adapted from time.Time.MarshalJSON to avoid allocation.
func appendJSONTime(s *handleState, t time.Time) {
	if y := t.Year(); y < 0 || y >= 10000 {
		// RFC 3339 is clear that years are 4 digits exactly.
		// See golang.org/issue/4556#c15 for more discussion.

//
// Each call to Handle results in a single serialized call to
// io.Writer.Write.
func (h *TextHandler) Handle(_ context.Context, r Record) error {
	return h.commonHandler.handle(r)
}

func appendTextValue(s *handleState, v Value) error {
	switch v.Kind() {
	case KindString:
		s.appendString(v.str())
	case KindTime:
		s.appendTime(v.time())
	case KindAny:
		if tm, ok := v.any.(encoding.TextMarshaler); ok {

		if got != test.want {
			t.Errorf("%v: got %s, want %s", test.value, got, test.want)
		}
	}
}

func jsonValueString(v Value) string {
	var buf []byte
	s := &handleState{h: &commonHandler{json: true}, buf: (*buffer.Buffer)(&buf)}
	if err := appendJSONValue(s, v); err != nil {
		s.appendError(err)
	}
	return string(buf)
}

func BenchmarkJSONHandler(b *testing.B) {