*
     * - _shouldn't_ be null, so we don't annotate it with @Nullable
     *
     * - _can_ be null without causing a runtime failure (because we don't want the interesting
     *   details of precondition failure to be hidden by an exception we throw about an unexpectedly
     *   null _failure message_)
     *
     * That combination upsets NullPointerTester, which wants any call that passes null for a

    @Override
    protected void doStart() {
      notifyFailed(new IllegalStateException("start failure"));
    }
  }

  private static class FailRunService extends NoOpService {
    @Override
    protected void doStart() {
      super.doStart();
      notifyFailed(new IllegalStateException("run failure"));
    }
  }

  private static class FailStopService extends NoOpService {
    @Override

    checkNotNull(throwable);
    if (!state.permitsPublicUserToTransitionTo(State.FAILURE)) {
      return false;
    }

    forceSetException(throwable);
    return true;
  }

  private void forceSetException(Throwable throwable) {
    this.throwable = throwable;
    this.state = State.FAILURE;
    notifyAndClearListeners();
  }

  @CanIgnoreReturnValue

   * particular Throwable.
   */
  private void handleException(Throwable throwable) {
    checkNotNull(throwable);

    if (allMustSucceed) {
      // As soon as the first one fails, make that failure the result of the output future.
      // The results of all other inputs are then ignored (except for logging any failures).
      boolean completedWithFailure = setException(throwable);
      if (!completedWithFailure) {

                if (logger.isDebugEnabled()) {
                    logger.debug("container was destroyed.");
                }
                return;
            }
            logger.warn("Failed to store a failure url.", e);
        }

        super.processCrawlingAccessException(objs);
        if (objs.length > 1 && objs[1] instanceof final UrlQueue<?> urlQueue) {

    public static final String ERRORS_storage_file_upload_failure = "{errors.storage_file_upload_failure}";

    /** The key of the message: The target file is not found in Storage. */
    public static final String ERRORS_storage_file_not_found = "{errors.storage_file_not_found}";

    /** The key of the message: Failed to download {0}. */
    public static final String ERRORS_storage_file_download_failure = "{errors.storage_file_download_failure}";

      seenExceptionsLocal = newConcurrentHashSet();
      /*
       * Other handleException() callers may see this as soon as we publish it. We need to populate
       * it with the initial failure before we do, or else they may think that the initial failure
       * has never been seen before.
       */
      addInitialException(seenExceptionsLocal);

      ATOMIC_HELPER.compareAndSetSeenExceptions(this, null, seenExceptionsLocal);

   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {
      assertFalse(message, getMap().containsKey(null));
    } catch (NullPointerException tolerated) {

        if (t instanceof Exception && !(t instanceof RuntimeException)) {
            eventCatapult.fire(ExecutionEvent.Type.ProjectFailed, currentSession, null, (Exception) t);
        }

        // reactor failure modes
        if (t instanceof RuntimeException || !(t instanceof Exception)) {
            // fail fast on RuntimeExceptions, Errors and "other" Throwables

        log(valueMap);
    }

    public void loginFailure(final OptionalThing<LoginCredential> credential) {
        final Map<String, String> valueMap = new LinkedHashMap<>();
        valueMap.put("action", Action.LOGIN_FAILURE.name());
        credential.ifPresent(c -> {
            valueMap.put("class", c.getClass().getSimpleName());
            if (c instanceof final FessCredential fessCredential) {