*/
  @CanIgnoreReturnValue
  @Override
  public boolean offer(E e) {
    if (e == null) throw new NullPointerException();
    final Monitor monitor = this.monitor;
    if (monitor.enterIf(notFull)) {
      try {
        insert(e);
        return true;
      } finally {
        monitor.leave();
      }
    } else {
      return false;
    }
  }

  /**

   * methods that do not take an explicit timeout value, a single test case is generated only if the
   * implicit timeout of that method matches the given timeoutsToUse. For example, enter() is
   * treated like enter(MAX, MILLIS) and tryEnter() is treated like enter(0, MILLIS).
   */
  private static void addTests(
      TestSuite suite,
      Method method,
      Scenario scenario,
      TimeoutsToUse timeoutsToUse,

   */
  public abstract static class Listener {
    /**
     * Called when the service initially becomes healthy.
     *
     * <p>This will be called at most once after all the services have entered the {@linkplain
     * State#RUNNING running} state. If any services fail during start up or {@linkplain
     * State#FAILED fail}/{@linkplain State#TERMINATED terminate} before all other services have

   */
  public abstract static class Listener {
    /**
     * Called when the service initially becomes healthy.
     *
     * <p>This will be called at most once after all the services have entered the {@linkplain
     * State#RUNNING running} state. If any services fail during start up or {@linkplain
     * State#FAILED fail}/{@linkplain State#TERMINATED terminate} before all other services have

   * methods that do not take an explicit timeout value, a single test case is generated only if the
   * implicit timeout of that method matches the given timeoutsToUse. For example, enter() is
   * treated like enter(MAX, MILLIS) and tryEnter() is treated like enter(0, MILLIS).
   */
  private static void addTests(
      TestSuite suite,
      Method method,
      Scenario scenario,
      TimeoutsToUse timeoutsToUse,

 * therefore every method of the listener will be called at most once. N.B. The {@link State#FAILED}
 * and {@link State#TERMINATED} states are terminal states, once a service enters either of these
 * states it cannot ever leave them.
 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes

   *
   * @since 27.0
   */
  @ForOverride
  protected void doCancelStart() {}

  @CanIgnoreReturnValue
  @Override
  public final Service startAsync() {
    if (monitor.enterIf(isStartable)) {
      try {
        snapshot = new StateSnapshot(STARTING);
        enqueueStartingEvent();
        doStart();
      } catch (Throwable startupFailure) {

 * therefore every method of the listener will be called at most once. N.B. The {@link State#FAILED}
 * and {@link State#TERMINATED} states are terminal states, once a service enters either of these
 * states it cannot ever leave them.
 *
 * <p>Implementors of this interface are strongly encouraged to extend one of the abstract classes

   *
   * @since 27.0
   */
  @ForOverride
  protected void doCancelStart() {}

  @CanIgnoreReturnValue
  @Override
  public final Service startAsync() {
    if (monitor.enterIf(isStartable)) {
      try {
        snapshot = new StateSnapshot(STARTING);
        enqueueStartingEvent();
        doStart();
      } catch (Throwable startupFailure) {

          @Override
          @CheckForNull
          protected Entry<E> computeNext() {
            if (iterator1.hasNext()) {
              Entry<? extends E> entry1 = iterator1.next();
              E element = entry1.getElement();
              int count = max(entry1.getCount(), multiset2.count(element));
              return immutableEntry(element, count);
            }
            while (iterator2.hasNext()) {