default:
        return new RegularImmutableSet<E>(delegate);
    }
  }

  private static <E> ImmutableSet<E> create(E... elements) {
    // Create the set first, to remove duplicates if necessary.
    Set<E> set = Sets.newLinkedHashSet();
    Collections.addAll(set, elements);
    for (E element : set) {
      checkNotNull(element);
    }

    switch (set.size()) {
      case 0:

    @Nullable Object[] alternatingKeysAndValues;
    int size;
    boolean entriesUsed;
    /**
     * If non-null, a duplicate key we found in a previous buildKeepingLast() or buildOrThrow()
     * call. A later buildOrThrow() can simply report this duplicate immediately.
     */
    @Nullable DuplicateKey duplicateKey;

    /**

   * collection in unspecified order.
   *
   * @param collection the elements that the set should contain
   * @return a new {@code CompactHashSet} containing those elements (minus duplicates)
   */
  public static <E extends @Nullable Object> CompactHashSet<E> create(
      Collection<? extends E> collection) {
    CompactHashSet<E> set = createWithExpectedSize(collection.size());
    set.addAll(collection);

                  }
                })
            .named("ImmutableMultiset.elementSet.asList")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.REJECTS_DUPLICATES_AT_CREATION,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

    return suite;
  }

 * elements.
 *
 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs
 * while adding a new pair.
 *

 * elements.
 *
 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs
 * while adding a new pair.
 *

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableSortedSet}, ordered by the specified comparator.
   *
   * <p>If the elements contain duplicates (according to the comparator), only the first duplicate
   * in encounter order will appear in the result.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})

   * @param columnKeys column keys that may be stored in the generated table
   * @throws NullPointerException if any of the provided keys is null
   * @throws IllegalArgumentException if {@code rowKeys} or {@code columnKeys} contains duplicates
   *     or if exactly one of {@code rowKeys} or {@code columnKeys} is empty.
   */
  public static <R, C, V> ArrayTable<R, C, V> create(
      Iterable<? extends R> rowKeys, Iterable<? extends C> columnKeys) {

   */

  /*
   * These generators also rely on consecutive integer inputs (not necessarily in order, but no
   * holes).
   */

  // SetCreationTester has some tests that pass in duplicates. Dedup them.
  private static <E extends Comparable<? super E>> SortedSet<E> nullCheckedTreeSet(E[] elements) {
    SortedSet<E> set = newTreeSet();
    for (E element : elements) {

                  }
                })
            .named("ForwardingMap[ImmutableMap] with standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.REJECTS_DUPLICATES_AT_CREATION,
                MapFeature.ALLOWS_ANY_NULL_QUERIES,
                CollectionFeature.KNOWN_ORDER)
            .createTestSuite());

    return suite;
  }