PreOrderIterator(T root) {
      this.stack = new ArrayDeque<>();
      stack.addLast(singletonIterator(checkNotNull(root)));
    }

    @Override
    public boolean hasNext() {
      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty
      T result = checkNotNull(itr.next());
      if (!itr.hasNext()) {

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testSingletonMapPollFirst() {
    assertEquals(a, navigableMap.pollFirstEntry());
    assertTrue(navigableMap.isEmpty());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapNearby() {
    assertNull(navigableMap.lowerEntry(k0()));
    assertNull(navigableMap.lowerKey(k0()));

  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testSingletonSetPollFirst() {
    assertEquals(a, navigableSet.pollFirst());
    assertTrue(navigableSet.isEmpty());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonSetNearby() {
    assertNull(navigableSet.lower(e0()));
    assertEquals(a, navigableSet.floor(e0()));

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testSingletonMapPollFirst() {
    assertEquals(a, navigableMap.pollFirstEntry());
    assertTrue(navigableMap.isEmpty());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapNearby() {
    assertNull(navigableMap.lowerEntry(k0()));
    assertNull(navigableMap.lowerKey(k0()));

        assertTrue(endLatch.await(30, TimeUnit.SECONDS), "All threads should complete within timeout");
        executor.shutdown();

        // Then - Verify no exceptions occurred
        if (!exceptions.isEmpty()) {
            fail("Concurrent operations caused exceptions: " + exceptions.get(0));
        }

        assertEquals(threadCount * opsPerThread, successCount.get(), "All operations should succeed");
    }

     */
    public List<String> getUrlList(final String userCode, final List<String> urlList) {
        if (urlList.isEmpty()) {
            return urlList;
        }

        return userInfoBhv.selectByPK(userCode).map(userInfo -> {
            final ListResultBean<FavoriteLog> list = favoriteLogBhv.selectList(cb2 -> {

     * @return A StreamResponse containing the file content.
     */
    @Execute
    public StreamResponse get$download(final String id) {
        final PathInfo pi = convertToItem(id);
        if (StringUtil.isEmpty(pi.getName())) {
            throwValidationErrorApi(messages -> messages.addErrorsStorageFileNotFound(GLOBAL));
        }
        return asStream(pi.getName()).contentTypeOctetStream().stream(out -> {
            try {

            this.canonical = urlStr.replace("..", "").replace(".", "");
        }

        @Override
        public String getName() {
            if (path == null || path.isEmpty() || path.equals("/")) {
                return host + "/"; // mimic the JVM behaviour for root or server
            }
            if (path.endsWith("/")) {

                try (Writer writer = Files.newBufferedWriter(outputFile, StandardCharsets.UTF_8)) {
                    writer.write(result);
                    if (!result.isEmpty()) {
                        writer.write(System.lineSeparator());
                    }
                }
            } else {
                System.out.print(result);
                System.out.flush();

                } else if ("".equals(artifact.getClassifier())) {
                    mains.add(artifact);
                }
            }
        }
        if (!mains.isEmpty() && !consumers.isEmpty()) {
            ArrayList<Artifact> result = new ArrayList<>(artifacts);
            for (Artifact main : mains) {
                result.remove(main);
                if (deployBuildPom) {