Collection<E> collection) {
      if (collection instanceof NavigableSet) {
        return Sets.unmodifiableNavigableSet((NavigableSet<E>) collection);
      } else if (collection instanceof SortedSet) {
        return Collections.unmodifiableSortedSet((SortedSet<E>) collection);
      } else if (collection instanceof Set) {
        return Collections.unmodifiableSet((Set<E>) collection);

   */
  public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(Iterable<E> elements) {
    if (elements instanceof ImmutableEnumSet) {
      return (ImmutableEnumSet<E>) elements;
    } else if (elements instanceof Collection) {
      Collection<E> collection = (Collection<E>) elements;
      if (collection.isEmpty()) {
        return ImmutableSet.of();
      } else {

      Collection<E> collection, @Nullable Object mutex) {
    if (collection instanceof SortedSet) {
      return sortedSet((SortedSet<E>) collection, mutex);
    }
    if (collection instanceof Set) {
      return set((Set<E>) collection, mutex);
    }
    if (collection instanceof List) {
      return list((List<E>) collection, mutex);
    }
    return collection(collection, mutex);
  }

      Collection<E> collection, @Nullable Object mutex) {
    if (collection instanceof SortedSet) {
      return sortedSet((SortedSet<E>) collection, mutex);
    }
    if (collection instanceof Set) {
      return set((Set<E>) collection, mutex);
    }
    if (collection instanceof List) {
      return list((List<E>) collection, mutex);
    }
    return collection(collection, mutex);
  }

            // notify listeners about "soft" project build failures only
            if (t instanceof Exception exception && !(t instanceof RuntimeException)) {
                eventCatapult.fire(ExecutionEvent.Type.ProjectFailed, session, null, exception);
            }

            // reactor failure modes
            if (t instanceof RuntimeException || !(t instanceof Exception)) {

                    ModelSource expectedParentSource = getParentPomFile(childModel, childSource);

                    if (expectedParentSource == null
                            || (expectedParentSource instanceof ModelSource2
                                    && !pomSource.equals(expectedParentSource))) {
                        parentData = readParentExternally(childModel, request, problems);
                    }

    return (Iterator<T>) EmptyModifiableIterator.INSTANCE;
  }

  /** Returns an unmodifiable view of {@code iterator}. */
  public static <T extends @Nullable Object> UnmodifiableIterator<T> unmodifiableIterator(
      Iterator<? extends T> iterator) {
    checkNotNull(iterator);
    if (iterator instanceof UnmodifiableIterator) {

        if (commandLine.hasOption(CLIManager.FAIL_ON_SEVERITY)) {
            String logLevelThreshold = commandLine.getOptionValue(CLIManager.FAIL_ON_SEVERITY);

            if (slf4jLoggerFactory instanceof LogLevelRecorder recorder) {
                LogLevelRecorder.Level level =
                        switch (logLevelThreshold.toLowerCase(Locale.ENGLISH)) {

        return build(toSource(modelSource), request);
    }

    @Deprecated
    static ModelSource toSource(org.apache.maven.model.building.ModelSource modelSource) {
        if (modelSource instanceof FileModelSource fms) {
            return Sources.buildSource(fms.getPath());
        } else {
            return new WrapModelSource(modelSource);
        }
    }

    @Override

    Iterator<Integer> source = asList(1, 2, 3).iterator();
    Iterator<List<Integer>> partitions = Iterators.partition(source, 2);
    assertTrue(partitions.next() instanceof RandomAccess);
    assertTrue(partitions.next() instanceof RandomAccess);
  }

  public void testPaddedPartition_badSize() {
    Iterator<Integer> source = singletonIterator(1);