public void testHashCode_containingNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    int expectedHashCode = 0;
    for (E element : elements) {
      expectedHashCode += (element == null) ? 0 : element.hashCode();
    }

    elements.add(null);
    collection = getSubjectGenerator().create(elements.toArray());
    assertEquals(

  /**
   * Returns the expected number of distinct elements given the specified elements. The number of
   * distinct elements is only computed if {@code elements} is an instance of {@code Multiset};
   * otherwise the default value of 11 is returned.
   */
  static int inferDistinctElements(Iterable<?> elements) {
    if (elements instanceof Multiset) {
      return ((Multiset<?>) elements).elementSet().size();
    }

  /**
   * Inserts the specified element into this priority queue.
   *
   * @param e the element to add
   * @return {@code true} (as specified by {@link Queue#offer})
   * @throws ClassCastException if the specified element cannot be compared with elements currently
   *     in the priority queue according to the priority queue's ordering
   * @throws NullPointerException if the specified element is null
   */

   * have been removed.
   *
   * <p><b>Warning:</b> Typical uses of the resulting iterator may produce an infinite loop. You
   * should use an explicit {@code break} or be certain that you will eventually remove all the
   * elements.
   *
   * <p>To cycle over the elements {@code n} times, use the following: {@code
   * Iterables.concat(Collections.nCopies(n, Arrays.asList(elements)))}
   *

   * Creates a new {@code EnumMultiset} containing the specified elements.
   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   * @throws IllegalArgumentException if {@code elements} is empty
   */
  public static <E extends Enum<E>> EnumMultiset<E> create(Iterable<E> elements) {
    Iterator<E> iterator = elements.iterator();

  /**
   * Returns the expected number of distinct elements given the specified elements. The number of
   * distinct elements is only computed if {@code elements} is an instance of {@code Multiset};
   * otherwise the default value of 11 is returned.
   */
  static int inferDistinctElements(Iterable<?> elements) {
    if (elements instanceof Multiset) {
      return ((Multiset<?>) elements).elementSet().size();
    }

   * Returns a fluent iterable whose iterators traverse first the elements of this fluent iterable,
   * followed by {@code elements}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code Stream.concat(thisStream, Stream.of(elements))}.
   *
   * @since 18.0
   */
  public final FluentIterable<E> append(E... elements) {
    return FluentIterable.concat(getDelegate(), Arrays.asList(elements));
  }

  /**

 * according to when the first occurrence of the element was added. When the multiset contains
 * multiple instances of an element, those instances are consecutive in the iteration order. If all
 * occurrences of an element are removed, after which that element is added to the multiset, the
 * element will appear at the end of the iteration.
 *

      Iterable<? extends E> elements) {
    checkNotNull(elements); // for GWT
    // Let ArrayList's sizing logic work, if possible
    return (elements instanceof Collection)
        ? new ArrayList<>((Collection<? extends E>) elements)
        : newArrayList(elements.iterator());
  }

  /**
   * Creates a <i>mutable</i> {@code ArrayList} instance containing the given elements; a very thin

   * default initial capacity, load factor, and concurrency settings.
   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   */
  public static <E> ConcurrentHashMultiset<E> create(Iterable<? extends E> elements) {