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()
	}