* (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code
   * Throwables.getCauseAs(e, IOException.class)} keeps {@code e} as the {@link
   * ClassCastException}'s cause.
   *
   * @throws ClassCastException if the cause cannot be cast to the expected type. The {@code
   *     ClassCastException}'s cause is {@code throwable}.

   * but mutates {@code multisetToModify} instead of returning a view.
   *
   * <p>In contrast, {@code multisetToModify.retainAll(multisetToRetain)} keeps all occurrences of
   * elements that appear at all in {@code multisetToRetain}, and deletes all occurrences of all
   * other elements.
   *

   * values.length) are all {@code null}.
   */
  @VisibleForTesting transient @Nullable Object @Nullable [] values;

  /**
   * Keeps track of metadata like the number of hash table bits and modifications of this data
   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note

   * but mutates {@code multisetToModify} instead of returning a view.
   *
   * <p>In contrast, {@code multisetToModify.retainAll(multisetToRetain)} keeps all occurrences of
   * elements that appear at all in {@code multisetToRetain}, and deletes all occurrences of all
   * other elements.
   *

    // Service b startup takes at least 353 millis, but starting the timer is delayed by at least
    // 150 milliseconds. so in a perfect world the timing would be 353-150=203ms, but since either
    // of our sleep calls can be arbitrarily delayed we should just assert that there is a time
    // recorded.
    assertThat(startupTimes.get(b)).isNotNull();
  }

  public void testServiceStartStop() {

                    String command;
                    while (true) {
                        try {
                            while (!reader.ready()) {
                                ThreadUtil.sleep(1000L);
                            }
                            command = reader.readLine().trim();
                            if (logger.isDebugEnabled()) {

                    } else {
                        final long interval = fessConfig.getThumbnailGeneratorIntervalAsInteger().longValue();
                        if (interval > 0) {
                            ThreadUtil.sleep(interval);
                        }
                    }
                } else {
                    logger.warn("Thumbnail generator is not available: name={}", generatorName);
                }

            } else if (behavior == 1) { // return null
              computeNullCount.incrementAndGet();
              return null;
            } else if (behavior == 2) { // slight delay before returning
              Thread.sleep(5);
              computeCount.incrementAndGet();
              return key;
            } else {
              computeCount.incrementAndGet();
              return key;
            }
          }
        };

   *       of a task are ignored.
   * </ol>
   *
   * <p>{@code RuntimeException}s thrown by tasks are simply logged and the executor keeps trucking.
   * If an {@code Error} is thrown, the error will propagate and execution will stop until the next
   * time a task is submitted.
   *

   * elements.length) are all {@code null}.
   */
  @VisibleForTesting transient @Nullable Object @Nullable [] elements;

  /**
   * Keeps track of metadata like the number of hash table bits and modifications of this data
   * structure (to make it possible to throw ConcurrentModificationException in the iterator). Note