private final EventBus bus;
    private final List<StringCatcher> catchers;

    Registrator(EventBus bus, List<StringCatcher> catchers) {
      this.bus = bus;
      this.catchers = catchers;
    }

    @Override
    public void run() {
      StringCatcher catcher = new StringCatcher();
      bus.register(catcher);
      catchers.add(catcher);
    }
  }

  /**
   * A collector for DeadEvents.

    private final EventBus bus;
    private final List<StringCatcher> catchers;

    Registrator(EventBus bus, List<StringCatcher> catchers) {
      this.bus = bus;
      this.catchers = catchers;
    }

    @Override
    public void run() {
      StringCatcher catcher = new StringCatcher();
      bus.register(catcher);
      catchers.add(catcher);
    }
  }

  /**
   * A collector for DeadEvents.

    bus = new AsyncEventBus(executor);
  }

  public void testBasicDistribution() {
    StringCatcher catcher = new StringCatcher();
    bus.register(catcher);

    // We post the event, but our Executor will not deliver it until instructed.
    bus.post(EVENT);

    List<String> events = catcher.getEvents();
    assertTrue("No events should be delivered synchronously.", events.isEmpty());

    bus = new AsyncEventBus(executor);
  }

  public void testBasicDistribution() {
    StringCatcher catcher = new StringCatcher();
    bus.register(catcher);

    // We post the event, but our Executor will not deliver it until instructed.
    bus.post(EVENT);

    List<String> events = catcher.getEvents();
    assertTrue("No events should be delivered synchronously.", events.isEmpty());

    bitSet.clear(0);
    bitSet.clear(1);
    matcher = useNew ? CharMatcher.whitespace() : OLD_WHITESPACE;
    teststring = newTestString(new Random(1), bitSet, percentMatching);
  }

  @Benchmark
  public int countIn(int reps) {
    int result = 0;
    CharMatcher matcher = this.matcher;
    String teststring = this.teststring;
    for (int i = 0; i < reps; i++) {
      result += matcher.countIn(teststring);
    }
    return result;

 * javadoc for details.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

 * javadoc for details.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class CommonPattern {
  public abstract CommonMatcher matcher(CharSequence t);

  public abstract String pattern();

  public abstract int flags();

  // Re-declare this as abstract to force subclasses to override.
  @Override
  public abstract String toString();

   * used in FilenameFilter.)
   */
  @Override
  public boolean accept(File dir, String fileName) {
    return pattern.matcher(fileName).matches();
  }

   */
  public static Throwable getRootCause(Throwable throwable) {
    // Keep a second pointer that slowly walks the causal chain. If the fast pointer ever catches
    // the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {

   */
  public static Throwable getRootCause(Throwable throwable) {
    // Keep a second pointer that slowly walks the causal chain. If the fast pointer ever catches
    // the slower pointer, then there's a loop.
    Throwable slowPointer = throwable;
    boolean advanceSlowPointer = false;

    Throwable cause;
    while ((cause = throwable.getCause()) != null) {