/**
 * Represents some operation performed by a test. Has a start and end instant.
 */
class NamedOperation {
    final String name
    final Instant start
    private final AtomicReference<Instant> end = new AtomicReference<>()

    NamedOperation(String name) {
        this.name = name
        this.start = new Instant(System.nanoTime())
    }

    @Override
    String toString() {

	traceEvStacks     // start of a section of the stack table [...traceEvStack]
	traceEvStack      // stack table entry [ID, ...{PC, func string ID, file string ID, line #}]
	traceEvStrings    // start of a section of the string dictionary [...traceEvString]
	traceEvString     // string dictionary entry [ID, length, string]
	traceEvCPUSamples // start of a section of CPU samples [...traceEvCPUSample]

	case trace.EventBad:
		if region.Start != nil {
			t.Errorf("expected nil region start event, got\n%s", region.Start.String())
		}
	case trace.EventStateTransition, trace.EventRegionBegin:
		if region.Start == nil {
			t.Error("expected non-nil region start event, got nil")
		}
		kind := region.Start.Kind()
		if kind != wantStart {
			t.Errorf("wanted region start event %s, got %s", wantStart, kind)
		}

        when:
        async {
            start {
                def cl = workerLeaseService.startWorker()
                instant.worker1
                thread.blockUntil.worker2Ready
                thread.block()
                instant.worker1Finished
                cl.leaseFinish()
            }
            start {
                thread.blockUntil.worker1
                instant.worker2Ready

		if len(tokens) != 2 {
			logger.Fatal(fmt.Errorf("invalid arguments passed to --ftp=%s", arg), "unable to start FTP server")
		}
		switch tokens[0] {
		case "address":
			host, portStr, err := net.SplitHostPort(tokens[1])
			if err != nil {
				logger.Fatal(fmt.Errorf("invalid arguments passed to --ftp=%s (%v)", arg, err), "unable to start FTP server")
			}
			port, err = strconv.Atoi(portStr)
			if err != nil {

    require(length < bytesOut.size - lastFrame.start)

    // Move everything from bytesOut into a new buffer.
    val fullBuffer = Buffer()
    bytesOut.read(fullBuffer, bytesOut.size)

    // Copy back all but what we're truncating.
    fullBuffer.read(bytesOut, lastFrame.start + length)
    outFrames.add(OutFrame(lastFrame.sequence, lastFrame.start, true))
    return writer
  }

		"Maximum number of active replication workers seen since server start")
	replicationMaxQueuedBytesMD = NewGaugeMD(replicationMaxQueuedBytes,
		"Maximum number of bytes queued for replication since server start")
	replicationMaxQueuedCountMD = NewGaugeMD(replicationMaxQueuedCount,
		"Maximum number of objects queued for replication since server start")
	replicationMaxDataTransferRateMD = NewGaugeMD(replicationMaxDataTransferRate,

type interval struct {
	start, end trace.Time
}

func (i interval) duration() time.Duration {
	return i.end.Sub(i.start)
}

func (i1 interval) overlap(i2 interval) time.Duration {
	// Assume start1 <= end1 and start2 <= end2
	if i1.end < i2.start || i2.end < i1.start {
		return 0
	}
	if i1.start < i2.start { // choose the later one
		i1.start = i2.start
	}

	EvGCStart           = 7  // GC start [timestamp, seq, stack id]
	EvGCDone            = 8  // GC done [timestamp]
	EvSTWStart          = 9  // GC mark termination start [timestamp, kind]
	EvSTWDone           = 10 // GC mark termination done [timestamp]
	EvGCSweepStart      = 11 // GC sweep start [timestamp, stack id]
	EvGCSweepDone       = 12 // GC sweep done [timestamp, swept, reclaimed]

        when:
        async {
            start {
                events1.each {
                    broadcaster.foo(it)
                }
            }
            start {
                events2.each {
                    broadcaster.foo(it)
                }
            }
            start {
                events3.each {
                    broadcaster.foo(it)