String testString = "abcdefgh";
    CharSource source = newCharSource(testString);
    int[] counter = new int[1];
    CharSource reader =
        new CharSource() {
          @Override
          public Reader openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }

	os.Exit(2)
}

func main() {
	log.SetFlags(0)
	log.SetPrefix("addr2line: ")
	counter.Open()

	// pprof expects this behavior when checking for addr2line
	if len(os.Args) > 1 && os.Args[1] == "--help" {
		printUsage(os.Stdout)
		os.Exit(0)
	}

	flag.Usage = usage
	flag.Parse()
	counter.Inc("addr2line/invocations")
	counter.CountFlags("addr2line/flag:", *flag.CommandLine)
	if flag.NArg() != 1 {
		usage()
	}

  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }

      void doIt(ImmutableLongArray.Builder builder, AtomicLong counter) {
        builder.add(counter.getAndIncrement());
      }
    },
    ADD_ARRAY {
      @Override
      void doIt(ImmutableLongArray.Builder builder, AtomicLong counter) {
        long[] array = new long[random.nextInt(10)];
        for (int i = 0; i < array.length; i++) {
          array[i] = counter.getAndIncrement();
        }
        builder.addAll(array);

While waiting and talking to your crush, from time to time, you check the number displayed on the counter to see if it's your turn already.

Then at some point, it finally is your turn. You go to the counter, get your burgers and come back to the table.

<img src="/img/async/concurrent-burgers/concurrent-burgers-06.png" class="illustration">

  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {
              throw new IllegalStateException("More than one source open");
            }

    }

    @Test
    @DisplayName("Test run method")
    void testRunMethod() throws Exception {
        AtomicInteger counter = new AtomicInteger(0);

        circuitBreaker.run(() -> counter.incrementAndGet());
        assertEquals(1, counter.get());

        SimpleCircuitBreaker.Statistics stats = circuitBreaker.getStatistics();
        assertEquals(1, stats.totalCalls);

		t.Helper()
		if err != nil {
			t.Fatal(err)
		}
	}

	// Add a version with tiered content, one with local content
	xl := xlMetaV2{}
	counter := 1
	report := func() {
		t.Helper()
		// t.Logf("versions (%d): len = %d", counter, len(xl.versions))
		counter++
	}
	fi := FileInfo{
		Volume:           "volume",
		Name:             "object-name",
		VersionID:        "00000000-0000-0000-0000-000000000001",

	sync.RWMutex
}

// Inc increments the api stats counter.
func (stats *HTTPAPIStats) Inc(api string) {
	if stats == nil {
		return
	}
	stats.Lock()
	defer stats.Unlock()
	if stats.apiStats == nil {
		stats.apiStats = make(map[string]int)
	}
	stats.apiStats[api]++
}

// Dec increments the api stats counter.
func (stats *HTTPAPIStats) Dec(api string) {
	if stats == nil {

type MetricType int

const (
	// CounterMT - represents a counter metric.
	CounterMT MetricType = iota
	// GaugeMT - represents a gauge metric.
	GaugeMT
	// HistogramMT - represents a histogram metric.
	HistogramMT
)

// rangeL - represents a range label.
const rangeL = "range"

func (mt MetricType) String() string {
	switch mt {
	case CounterMT:
		return "counter"
	case GaugeMT:
		return "gauge"