final Executor executor() {
    return executor;
  }

  /** Handles the given exception thrown by a subscriber with the given context. */
  void handleSubscriberException(Throwable e, SubscriberExceptionContext context) {
    checkNotNull(e);
    checkNotNull(context);
    try {
      exceptionHandler.handleException(e, context);
    } catch (Throwable e2) {

  final void dispatchEvent(Object event) {
    executor.execute(
        () -> {
          try {
            invokeSubscriberMethod(event);
          } catch (InvocationTargetException e) {
            bus.handleSubscriberException(e.getCause(), context(event));
          }
        });
  }

  /**
   * Invokes the subscriber method. This method can be overridden to make the invocation
   * synchronized.
   */
  @VisibleForTesting