*
   * @param multiset the presumed-immutable multiset
   * @param sampleElement an element of the same type as that contained by {@code multiset}. {@code
   *     multiset} may or may not have {@code sampleElement} as a member.
   */
  public static <E extends @Nullable Object> void assertMultisetIsUnmodifiable(
      Multiset<E> multiset, E sampleElement) {
    Multiset<E> copy = LinkedHashMultiset.create(multiset);

 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns
 * {@code @ParametricNullness E}, which means:
 *
 * <ul>
 *   <li>{@code getElement} on a {@code Multiset.Entry<@NonNull String>} returns {@code @NonNull
 *       String}.
 *   <li>{@code getElement} on a {@code Multiset.Entry<@Nullable String>} returns {@code @Nullable
 *       String}.
 * </ul>
 *

  }

  public void testMultisetsSpliterator() {
    Multiset<String> multiset = TreeMultiset.create();
    multiset.add("a", 3);
    multiset.add("b", 1);
    multiset.add("c", 2);

    List<String> actualValues = new ArrayList<>();
    multiset.spliterator().forEachRemaining(actualValues::add);
    assertThat(multiset).containsExactly("a", "a", "a", "b", "c", "c").inOrder();
  }

  }

  @Generates
  static <E> Multiset<E> generateMultiset(@Nullable E freshElement) {
    return generateHashMultiset(freshElement);
  }

  @Generates
  static <E> HashMultiset<E> generateHashMultiset(@Nullable E freshElement) {
    HashMultiset<E> multiset = HashMultiset.create();
    multiset.add(freshElement);
    return multiset;
  }

  @Generates

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> adjacentNodesReference;

  @Override
  public Set<N> adjacentNodes() {
    return Collections.unmodifiableSet(adjacentNodesMultiset().elementSet());
  }

  private Multiset<N> adjacentNodesMultiset() {
    Multiset<N> adjacentNodes = getReference(adjacentNodesReference);
    if (adjacentNodes == null) {

  }

  public void testClassCreate() {
    Multiset<Color> ms = EnumMultiset.create(Color.class);
    ms.add(Color.RED);
    ms.add(Color.YELLOW);
    ms.add(Color.RED);
    assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

  public void testCollectionCreate() {

  public void testCreation_noArgs() {
    Multiset<String> multiset = ImmutableMultiset.of();
    assertTrue(multiset.isEmpty());
  }

  public void testCreation_oneElement() {
    Multiset<String> multiset = ImmutableMultiset.of("a");
    assertEquals(HashMultiset.create(asList("a")), multiset);
  }

  public void testCreation_twoElements() {
    Multiset<String> multiset = ImmutableMultiset.of("a", "b");

  /*
   * As the class docs say, this test only makes sense for collections that define equals().
   * Accordingly, our testing framework adds it only when testing an implementation of List, Set, or
   * Multiset.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testReserialize() {
    assertEquals(SerializableTester.reserialize(actualContents()), actualContents());
  }

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> predecessorsReference;

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(predecessorsMultiset().elementSet());
  }

  private Multiset<N> predecessorsMultiset() {
    Multiset<N> predecessors = getReference(predecessorsReference);
    if (predecessors == null) {

  }

  @LazyInit private transient @Nullable Reference<Multiset<N>> predecessorsReference;

  @Override
  public Set<N> predecessors() {
    return Collections.unmodifiableSet(predecessorsMultiset().elementSet());
  }

  private Multiset<N> predecessorsMultiset() {
    Multiset<N> predecessors = getReference(predecessorsReference);
    if (predecessors == null) {