public final class MyClassWithTracing {
  private static final Tracer tracer = Tracing.getTracer();

  public static void doWork() {
    // Create a child Span of the current Span. Always record events for this span and force it to 
    // be sampled. This makes it easier to try out the example, but unless you have a clear use 
    // case, you don't need to explicitly set record events or sampler.
    try (Scope ss = 
         tracer.spanBuilder("MyChildWorkSpan")
           .setRecordEvents(true)
           .setSampler(Samplers.alwaysSample())
           .startScopedSpan()) {
      doInitialWork();
      tracer.getCurrentSpan().addAnnotation("Finished initial work");
      doFinalWork();
    }
  }

  private static void doInitialWork() {
    // ...
    tracer.getCurrentSpan().addAnnotation("Important.");
    // ...
  }

  private static void doFinalWork() {
    // ...
    tracer.getCurrentSpan().addAnnotation("More important.");
    // ...
  }
}

public final class QuickStart {
  private static final Tagger tagger = Tags.getTagger();
  private static final ViewManager viewManager = Stats.getViewManager();
  private static final StatsRecorder statsRecorder = Stats.getStatsRecorder();

  // frontendKey allows us to break down the recorded data
  private static final TagKey FRONTEND_KEY = TagKey.create("myorg_keys_frontend");

  // videoSize will measure the size of processed videos.
  private static final MeasureLong VIDEO_SIZE = MeasureLong.create(
      "my.org/measure/video_size", "size of processed videos", "By");

  // Create view to see the processed video size distribution broken down by frontend.
  // The view has bucket boundaries (0, 256, 65536) that will group measure values into
  // histogram buckets.
  private static final View.Name VIDEO_SIZE_VIEW_NAME = View.Name.create("my.org/views/video_size");
  private static final View VIDEO_SIZE_VIEW = View.create(
      VIDEO_SIZE_VIEW_NAME,
      "processed video size over time",
      VIDEO_SIZE,
      Aggregation.Distribution.create(BucketBoundaries.create(Arrays.asList(0.0, 256.0, 65536.0))),
      Collections.singletonList(FRONTEND_KEY),
      Cumulative.create());

  private static void initialize() {
    // ...
    viewManager.registerView(VIDEO_SIZE_VIEW);
  }

  private static void processVideo() {
    try (Scope scopedTags =
           tagger
             .currentBuilder()
             .put(FRONTEND_KEY, TagValue.create("mobile-ios9.3.5"))
             .buildScoped()) {
      // Processing video.
      // ...

      // Record the processed video size.
      statsRecorder.newMeasureMap().put(VIDEO_SIZE, 25648).record();
    }
  }

  private static void printStats() {
    ViewData viewData = viewManager.getView(VIDEO_SIZE_VIEW_NAME);
    System.out.println(
      String.format("Recorded stats for %s:\n %s", VIDEO_SIZE_VIEW_NAME.asString(), viewData));
  }
}