public void testEquals_yes() {
    assertTrue(
        "multiset doesn't equal a multiset with the same elements",
        getMultiset().equals(HashMultiset.create(getSampleElements())));
  }

  public void testEquals_differentSize() {
    Multiset<E> other = HashMultiset.create(getSampleElements());
    other.add(e0());
    assertFalse("multiset equals a multiset with a different size", getMultiset().equals(other));
  }

  private static class MutateTask implements Callable<int[]> {
    private final ConcurrentHashMultiset<String> multiset;
    private final ImmutableList<String> keys;
    private final Random random = new Random();

    private MutateTask(ConcurrentHashMultiset<String> multiset, ImmutableList<String> keys) {
      this.multiset = multiset;
      this.keys = keys;
    }

    @Override
    public int[] call() throws Exception {

    // "extends Object" works around https://github.com/typetools/checker-framework/issues/3013
    SerializedForm(Multiset<? extends Object> multiset) {
      int distinct = multiset.entrySet().size();
      elements = new Object[distinct];
      counts = new int[distinct];
      int i = 0;
      for (Entry<? extends Object> entry : multiset.entrySet()) {
        elements[i] = entry.getElement();
        counts[i] = entry.getCount();
        i++;

   */
  protected class StandardElementSet extends Multisets.ElementSet<E> {
    /** Constructor for use by subclasses. */
    public StandardElementSet() {}

    @Override
    Multiset<E> multiset() {
      return ForwardingMultiset.this;
    }

    @Override
    public Iterator<E> iterator() {
      return Multisets.elementIterator(multiset().entrySet().iterator());
    }
  }

  /**

        }
      }
      return oldCount;
    }

    @Override
    public Set<Multiset.Entry<K>> entrySet() {
      return new Multisets.EntrySet<K>() {

        @Override
        Multiset<K> multiset() {
          return Keys.this;
        }

        @Override
        public Iterator<Multiset.Entry<K>> iterator() {
          return Keys.this.entryIterator();
        }

        @Override

        new ImmutableMultiset.Builder<String>().addCopies("x", 10).build();
    multiset.addAll(adds);
    assertEquals(1, addCalls.get());
  }

  public void testRemoveUnsupported() {
    Multiset<String> multiset = new NoRemoveMultiset<>();
    multiset.add("a");
    assertThrows(UnsupportedOperationException.class, () -> multiset.remove("a"));
    assertTrue(multiset.contains("a"));
  }

        (multiset1, multiset2) -> {
          multiset1.addAll(multiset2);
          return multiset1;
        },
        (Multiset<E> multiset) -> ImmutableMultiset.copyFromEntries(multiset.entrySet()));
  }

  static <T extends @Nullable Object, E extends @Nullable Object, M extends Multiset<E>>
      Collector<T, ?, M> toMultiset(
          Function<? super T, E> elementFunction,

  }

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

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

    return (result == null) ? entrySet = createEntrySet() : result;
  }

  Set<Entry<E>> createEntrySet() {
    @WeakOuter
    class EntrySetImpl extends Multisets.EntrySet<E> {
      @Override
      Multiset<E> multiset() {
        return DescendingMultiset.this;
      }

      @Override
      public Iterator<Entry<E>> iterator() {
        return entryIterator();
      }

@GwtCompatible
public enum MultisetFeature implements Feature<Multiset> {
  /**
   * Indicates that elements from {@code Multiset.entrySet()} update to reflect changes in the
   * backing multiset.
   */
  ENTRIES_ARE_VIEWS;

  @Override
  public Set<Feature<? super Multiset>> getImpliedFeatures() {
    return emptySet();
  }

  @Retention(RetentionPolicy.RUNTIME)
  @Inherited