* accepts non-{@code Collection} iterables and empty iterables.
   */
  public static <E extends Enum<E>> EnumSet<E> newEnumSet(
      Iterable<E> iterable, Class<E> elementType) {
    EnumSet<E> set = EnumSet.noneOf(elementType);
    Iterables.addAll(set, iterable);
    return set;
  }

  // HashSet

  /**

  // create(Enum1.class) is equal to create(Enum2.class) but testEquals() expects otherwise.
  // For the same reason, we need to skip create(Iterable, Class).
  private static class EnumMultisetFactory {
    @Keep // used reflectively by testEquals
    public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
      return EnumMultiset.create(elements);
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection

    SEQUENTIAL {
      @Override
      final <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
          A result(Collector<T, A, R> collector, Iterable<T> inputs) {
        A accum = collector.supplier().get();
        for (T input : inputs) {
          collector.accumulator().accept(accum, input);
        }
        return accum;
      }
    },

    POST_ORDER {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.postOrderTraversal(root);
      }
    },
    BREADTH_FIRST {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.breadthFirstTraversal(root);
      }
    };

    abstract <T> Iterable<T> view(T root, TreeTraverser<T> viewer);
  }

    Iterable<Double> iterable = iterable(Collections.<Double>emptySet());
    assertThat(ImmutableDoubleArray.copyOf(iterable)).isSameInstanceAs(ImmutableDoubleArray.of());
  }

  public void testCopyOf_iterable_notCollection_nonempty() {
    List<Double> list = Arrays.asList(0.0, 1.0, 3.0);
    ImmutableDoubleArray iia = ImmutableDoubleArray.copyOf(iterable(list));
    list.set(2, 2.0);

    /**
     * Returns an {@link Iterable} that wraps an {@link Enumeration} for use in a for-each statement.
     *
     * @param <T> the element type
     * @param enumeration the enumeration (must not be {@literal null})
     * @return an {@link Iterable} wrapping the enumeration
     */
    public static <T> Iterable<T> iterable(final Enumeration<T> enumeration) {

  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      int startIndex) {
    super(steps, elementsToInsert, features, expectedElements, KnownOrder.KNOWN_ORDER, startIndex);
  }

  @Override
  protected final Iterable<? extends Stimulus<E, ? super ListIterator<E>>> getStimulusValues() {

      Iterable<? extends E> elements) {
    Comparable<?>[] array = Iterables.toArray(elements, new Comparable<?>[0]);
    checkElementsNotNull((Object[]) array);
    Arrays.sort(array);
    return asImmutableList(array);
  }

  public static <E> ImmutableList<E> sortedCopyOf(
      Comparator<? super E> comparator, Iterable<? extends E> elements) {
    checkNotNull(comparator);

  }

  private static <T> List<T> defensiveCopy(T... array) {
    return defensiveCopy(Arrays.asList(array));
  }

  static <T> List<T> defensiveCopy(Iterable<T> iterable) {
    ArrayList<T> list = new ArrayList<>();
    for (T element : iterable) {
      list.add(checkNotNull(element));
    }
    return list;
  }

  private Predicates() {}

  }

  @Override
  public SampleElements<String> sampleValues() {
    return new SampleElements<>("January", "February", "March", "April", "May");
  }

  @Override
  public Collection<String> createCollection(Iterable<? extends String> values) {
    return copyToSet(values);
  }

  @Override
  public final SetMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")