new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    return ImmutableMultiset.copyOf(elements).elementSet();
                  }
                })
            .named("ImmutableMultiset, element set")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.SERIALIZABLE,

   * objects per entry.  Instead we use an open-addressed hash table.  This design is basically
   * equivalent to RegularImmutableSet, save that instead of having a hash table containing the
   * elements directly and null for empty positions, we store indices of the keys in the hash table,
   * and ABSENT for empty positions.  We then look up the keys in alternatingKeysAndValues.
   *

  private SortedIterables() {}

  /**
   * Returns {@code true} if {@code elements} is a sorted collection using an ordering equivalent to
   * {@code comparator}.
   */
  public static boolean hasSameComparator(Comparator<?> comparator, Iterable<?> elements) {
    checkNotNull(comparator);
    checkNotNull(elements);
    Comparator<?> comparator2;
    if (elements instanceof SortedSet) {
      comparator2 = comparator((SortedSet<?>) elements);

    @Override
    public List<String> create(String[] elements) {
      ImmutableMap.Builder<String, Integer> builder = ImmutableMap.builder();
      for (int i = 0; i < elements.length; i++) {
        builder.put(elements[i], i);
      }
      return builder.buildOrThrow().keySet().asList();
    }
  }

  public static class ImmutableMapValueListGenerator extends TestStringListGenerator {

    List<E> list = new ArrayList<>();
    addAll(list, elements);
    return list;
  }

  public static <E extends @Nullable Object> List<E> copyToList(E[] elements) {
    return copyToList(asList(elements));
  }

  // Clone of Sets.newLinkedHashSet
  public static <E extends @Nullable Object> Set<E> copyToSet(Iterable<? extends E> elements) {
    Set<E> set = new LinkedHashSet<>();

  /**
   * A collector that converts a stream of zero or one elements to an {@code Optional}.
   *
   * @throws IllegalArgumentException if the stream consists of two or more elements.
   * @throws NullPointerException if any element in the stream is {@code null}.
   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.

          .sampleValues();
    }

    @Override
    public Collection<V> create(Object... elements) {
      K k =
          ((TestMultimapGenerator<K, V, M>) multimapGenerator.getInnerGenerator())
              .sampleKeys()
              .e0();
      Object[] entries = new Object[elements.length];
      for (int i = 0; i < elements.length; i++) {
        @SuppressWarnings("unchecked") // These come from Entry<K, V> objects somewhere.

  public SampleElements<Entry<K, V>> samples() {
    return SampleElements.mapEntries(keys, values);
  }

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    arraycopy(elements, 0, entries, 0, elements.length);
    return createFromEntries(entries);
  }

  public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

  @Override

    Iterator<E> iterator = collection.iterator();
    Object element = iterator.next();
    // If it's an Entry, it may become invalid once it's removed from the Map. Copy it.
    if (element instanceof Entry) {
      Entry<?, ?> entry = (Entry<?, ?>) element;
      element = mapEntry(entry.getKey(), entry.getValue());
    }
    assertTrue(collection.contains(element)); // sanity check
    iterator.remove();

    return new Unhashables();
  }

  @Override
  public T create(Object... elements) {
    UnhashableObject[] array = createArray(elements.length);
    int i = 0;
    for (Object e : elements) {
      array[i++] = (UnhashableObject) e;
    }
    return create(array);
  }

  /**
   * Creates a new collection containing the given elements; implement this method instead of {@link
   * #create(Object...)}.
   */