@CanIgnoreReturnValue
    public Builder<E> add(E... elements) {
      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterable<? extends E> elements) {
      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }

    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableSortedMultiset}.
     *
     * @param elements the elements to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E... elements) {
      for (E element : elements) {

  }

  /**
   * Creates an {@code ArrayDeque} containing the elements of the specified iterable, in the order
   * they are returned by the iterable's iterator.
   *
   * @since 12.0
   */
  public static <E> ArrayDeque<E> newArrayDeque(Iterable<? extends E> elements) {
    if (elements instanceof Collection) {
      return new ArrayDeque<>((Collection<? extends E>) elements);
    }
    ArrayDeque<E> deque = new ArrayDeque<>();

    /**
     * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
     *
     * @param elements the elements to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E... elements) {
      super.add(elements);
      return this;
    }

            + " even if some elements are null.",
        getSet().equals(MinimalSet.from(elements)));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherContainsNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    elements.add(null);
    Set<E> other = MinimalSet.from(elements);

    assertFalse(

            + " even if some elements are null.",
        getSet().equals(MinimalSet.from(elements)));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  public void testEquals_otherContainsNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    elements.add(null);
    Set<E> other = MinimalSet.from(elements);

    assertFalse(

    protected List<Byte> create(Byte[] elements) {
      return asList(elements);
    }
  }

  public static final class BytesAsListHeadSubListGenerator extends TestByteListGenerator {
    @Override
    protected List<Byte> create(Byte[] elements) {
      Byte[] suffix = {Byte.MIN_VALUE, Byte.MAX_VALUE};
      Byte[] all = concat(elements, suffix);
      return asList(all).subList(0, elements.length);
    }
  }

    protected List<Character> create(Character[] elements) {
      return asList(elements);
    }
  }

  public static final class CharsAsListHeadSubListGenerator extends TestCharListGenerator {
    @Override
    protected List<Character> create(Character[] elements) {
      Character[] suffix = {Character.MIN_VALUE, Character.MAX_VALUE};
      Character[] all = concat(elements, suffix);

    @Override
    protected List<Double> create(Double[] elements) {
      return asList(elements);
    }
  }

  public static final class DoublesAsListHeadSubListGenerator extends TestDoubleListGenerator {
    @Override
    protected List<Double> create(Double[] elements) {
      Double[] suffix = {Double.MIN_VALUE, Double.MAX_VALUE};
      Double[] all = concat(elements, suffix);
      return asList(all).subList(0, elements.length);

    @Override
    protected List<String> create(String[] elements) {
      String[] suffix = {"f", "g"};
      String[] all = new String[elements.length + suffix.length];
      System.arraycopy(elements, 0, all, 0, elements.length);
      System.arraycopy(suffix, 0, all, elements.length, suffix.length);
      return ImmutableList.copyOf(all).subList(0, elements.length);
    }
  }