*
   * @since 15.0
   */
  public static Stopwatch createStarted(Ticker ticker) {
    return new Stopwatch(ticker).start();
  }

  Stopwatch() {
    this.ticker = Ticker.systemTicker();
  }

  Stopwatch(Ticker ticker) {
    this.ticker = checkNotNull(ticker, "ticker");
  }

  /**

func newSignV4ChunkedReader(req *http.Request, trailer bool) (io.ReadCloser, APIErrorCode) {
	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)

		},
		{
			val:   0.79,
			label: labels[2],
		},
	}
	ticker := time.NewTicker(1 * time.Millisecond)
	defer ticker.Stop()
	for _, obs := range observations {
		// Send observations once every 1ms, to simulate delay between
		// observations. This is to test the channel based
		// synchronization used internally.
		select {
		case <-ticker.C:
			ttfbHist.With(prometheus.Labels{"api": obs.label}).Observe(obs.val)
		}

      HeldCertificate.Builder()
        .serialNumber(1L)
        .certificateAuthority(4)
        .commonName("attacker ca")
        .build()
    val attackerIntermediate =
      HeldCertificate.Builder()
        .serialNumber(2L)
        .certificateAuthority(3)
        .commonName("attacker")
        .signedBy(attackerCa)
        .build()
    val pinnedRoot =
      HeldCertificate.Builder()

	err := checkTracing(cli, &messages)
	assert.NoError(t, err)
	assert.Equal(t, 1, len(messages))

	expectedOutput := msg.NewUpdateIncompatibility(ObjectToInstance(zipkinSvc),
		"meshConfig.defaultConfig.tracer", "1.21",
		"tracing is no longer by default enabled to send to 'zipkin.istio-system.svc'; "+
			"follow https://istio.io/latest/docs/tasks/observability/distributed-tracing/telemetry-api/",
		"1.21")

	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages
	wTimer          *time.Ticker // ticker for calculating active workers
	qTimer          *time.Ticker // ticker for calculating queue stats
}

func (r *ReplicationStats) trackEWMA() {
	for {
		select {
		case <-r.movingAvgTicker.C:

	cs, err := GetContentChecksum(req.Header)
	if err != nil {
		return ErrInvalidChecksum
	}
	if cs == nil {
		return nil
	}
	r.contentHash = *cs
	if cs.Type.Trailing() {
		r.trailer = req.Trailer
	}
	return r.AddNonTrailingChecksum(cs, ignoreValue)
}

// AddChecksumNoTrailer will add checksum checks as specified in
// https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html

		return FormatUnknown
	}

	// Guess the magic values.
	magic := string(b.toUSTAR().magic())
	version := string(b.toUSTAR().version())
	trailer := string(b.toSTAR().trailer())
	switch {
	case magic == magicUSTAR && trailer == trailerSTAR:
		return formatSTAR
	case magic == magicUSTAR:
		return FormatUSTAR | FormatPAX
	case magic == magicGNU && version == versionGNU:
		return FormatGNU

MIT License

Copyright (c) 2019-present Faye Amacker

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is

const unsignedPayload = "UNSIGNED-PAYLOAD"

// http Header "x-amz-content-sha256" == "STREAMING-UNSIGNED-PAYLOAD-TRAILER" indicates that the
// client did not calculate sha256 of the payload and there is a trailer.
const unsignedPayloadTrailer = "STREAMING-UNSIGNED-PAYLOAD-TRAILER"

// skipContentSha256Cksum returns true if caller needs to skip
// payload checksum, false if not.