() -> TreeMultiset.create(comparator),
        (multiset, t) ->
            multiset.add(checkNotNull(elementFunction.apply(t)), countFunction.applyAsInt(t)),
        (multiset1, multiset2) -> {
          multiset1.addAll(multiset2);
          return multiset1;
        },
        (Multiset<E> multiset) -> copyOfSortedEntries(comparator, multiset.entrySet()));
  }

  /**

   *
   * @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);

    assertEquals(original, copy);
    assertTrue(copy instanceof ImmutableSet);
    return copy;
  }

  @CanIgnoreReturnValue
  @GwtIncompatible // SerializableTester
  static <E> Multiset<E> reserializeAndAssertLenient(Multiset<E> original) {
    Multiset<E> copy = reserialize(original);
    assertEquals(original, copy);
    assertTrue(copy instanceof ImmutableMultiset);
    return copy;
  }

  @CanIgnoreReturnValue

 * 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>
 *

  static class ElementSet<E extends @Nullable Object> extends Multisets.ElementSet<E>
      implements SortedSet<E> {
    @Weak private final SortedMultiset<E> multiset;

    ElementSet(SortedMultiset<E> multiset) {
      this.multiset = multiset;
    }

    @Override
    final SortedMultiset<E> multiset() {
      return multiset;
    }

    @Override
    public Iterator<E> iterator() {

  }

  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();
  }

    setCountCheckReturnValue(element, count);

    assertEquals(
        "multiset.count() should return the value passed to setCount()",
        count,
        getMultiset().count(element));

    int size = 0;
    for (Multiset.Entry<E> entry : getMultiset().entrySet()) {
      size += entry.getCount();
    }
    assertEquals(
        "multiset.size() should be the sum of the counts of all entries",
        size,

    Multiset<E> multiset = LinkedHashMultiset.create();
    Iterators.addAll(multiset, elements);
    return copyFromEntries(multiset.entrySet());
  }

  private static <E> ImmutableMultiset<E> copyFromElements(E... elements) {
    Multiset<E> multiset = LinkedHashMultiset.create();
    Collections.addAll(multiset, elements);
    return copyFromEntries(multiset.entrySet());
  }

  }

  @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) {

  }

  @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