public void testSerialization_asList() {
    ImmutableMultiset<String> multiset = ImmutableMultiset.of("a", "a", "b", "b", "b");
    SerializableTester.reserializeAndAssert(multiset.asList());
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableMultiset.of(), ImmutableMultiset.of())
        .addEqualityGroup(ImmutableMultiset.of(1), ImmutableMultiset.of(1))

  public void testSerialization_asList() {
    ImmutableMultiset<String> multiset = ImmutableMultiset.of("a", "a", "b", "b", "b");
    SerializableTester.reserializeAndAssert(multiset.asList());
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(ImmutableMultiset.of(), ImmutableMultiset.of())
        .addEqualityGroup(ImmutableMultiset.of(1), ImmutableMultiset.of(1))

  }

  /** All the ways to create an ImmutableMultiset. */
  enum ConstructionPathway implements Construction<Multiset<Object>> {
    COPY_OF_COLLECTION {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys);
      }
    },
    COPY_OF_ITERATOR {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {

          .put(
              SortedSetMultimap.class,
              Multimaps.unmodifiableSortedSetMultimap(TreeMultimap.create()))
          .put(Multiset.class, ImmutableMultiset.of())
          .put(ImmutableMultiset.class, ImmutableMultiset.of())
          .put(SortedMultiset.class, ImmutableSortedMultiset.of())
          .put(ImmutableSortedMultiset.class, ImmutableSortedMultiset.of())

                  @Override
                  protected Multiset<String> create(String[] elements) {
                    return new StandardImplForwardingMultiset<>(ImmutableMultiset.copyOf(elements));
                  }
                })
            .named("ForwardingMultiset[ImmutableMultiset] with standard " + "implementations")
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

                  @Override
                  protected Multiset<String> create(String[] elements) {
                    return new StandardImplForwardingMultiset<>(ImmutableMultiset.copyOf(elements));
                  }
                })
            .named("ForwardingMultiset[ImmutableMultiset] with standard " + "implementations")
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_QUERIES)
            .createTestSuite());

          public int add(String element, int occurrences) {
            addCalls.incrementAndGet();
            return super.add(element, occurrences);
          }
        };
    ImmutableMultiset<String> adds =
        new ImmutableMultiset.Builder<String>().addCopies("x", 10).build();
    multiset.addAll(adds);
    assertEquals(1, addCalls.get());
  }

  public void testRemoveUnsupported() {

          public int add(String element, int occurrences) {
            addCalls.incrementAndGet();
            return super.add(element, occurrences);
          }
        };
    ImmutableMultiset<String> adds =
        new ImmutableMultiset.Builder<String>().addCopies("x", 10).build();
    multiset.addAll(adds);
    assertEquals(1, addCalls.get());
  }

  public void testRemoveUnsupported() {

   * {@code stream.map(function).collect(Collectors.toCollection(supplier))}.
   *
   * <p>To collect to an {@link ImmutableMultiset}, use {@link
   * ImmutableMultiset#toImmutableMultiset}.
   *
   * @since 33.2.0 (available since 22.0 in guava-jre)
   */
  @SuppressWarnings("Java7ApiChecker")

          .put(
              SortedSetMultimap.class,
              Multimaps.unmodifiableSortedSetMultimap(TreeMultimap.create()))
          .put(Multiset.class, ImmutableMultiset.of())
          .put(ImmutableMultiset.class, ImmutableMultiset.of())
          .put(SortedMultiset.class, ImmutableSortedMultiset.of())
          .put(ImmutableSortedMultiset.class, ImmutableSortedMultiset.of())