int h2 = Objects.hashCode(Integer.valueOf(1), new String("two"), Double.valueOf(3.0));
    // repeatable
    assertEquals(h1, h2);

    // These don't strictly need to be true, but they're nice properties.
    assertTrue(Objects.hashCode(1, 2, null) != Objects.hashCode(1, 2));
    assertTrue(Objects.hashCode(1, 2, null) != Objects.hashCode(1, null, 2));
    assertTrue(Objects.hashCode(1, null, 2) != Objects.hashCode(1, 2));

  public void testPutAllNullValueSingle_unsupported() {
    multimap().putAll(k1(), Lists.newArrayList((V) null));
    expectUnchanged();
  }

  // In principle, it would be nice to apply these two tests to keys with existing values, too.

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
  public void testPutAllNullValueNullLast_unsupported() {
    int size = getNumElements();

   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked
   *       that when equal parameters are passed, the result instance should also be equal; and vice
   *       versa.
   *   <li>If a non-private constructor or non-private static factory method exists:
   *       <ul>
   *         <li>Test will fail if default value for a parameter cannot be determined.

   *       instances.
   *   <li>For the constructor or static factory method used to construct instances, it's checked
   *       that when equal parameters are passed, the result instance should also be equal; and vice
   *       versa.
   *   <li>Inequality check is not performed against state mutation methods such as {@link
   *       List#add}, or functional update methods such as {@link

   *     the size method
   */
  public static <T extends @Nullable Object> Collection<T> misleadingSizeCollection(int delta) {
    // It would be nice to be able to return a real concurrent
    // collection like ConcurrentLinkedQueue, so that e.g. concurrent
    // iteration would work, but that would not be GWT-compatible.

    Collections.shuffle(hashCodes);
    HashCode hashCode2 = Hashing.combineUnordered(hashCodes);

    assertEquals(hashCode1, hashCode2);
  }

  // This isn't specified by contract, but it'll still be nice to know if this behavior changes.
  public void testConcatenating_equals() {
    new EqualsTester()
        .addEqualityGroup(Hashing.concatenating(asList(Hashing.md5())))

  }

  /**
   * Generates a decorated collection that remains consistent with the values in the multimap for
   * the provided key. Changes to the multimap may alter the returned collection, and vice versa.
   */
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedCollection(key, collection, null);
  }

  final List<V> wrapList(

   */
  Collection<V> get(@ParametricNullness K key);

  /**
   * Returns a view collection of all <i>distinct</i> keys contained in this multimap. Note that the
   * key set contains a key if and only if this multimap maps that key to at least one value.
   *
   * <p>Changes to the returned set will update the underlying multimap, and vice versa. However,

   * <i>adding</i> to the returned set is not possible.
   */
  @Override
  public Set<K> keySet() {
    return super.keySet();
  }

  /**
   * Returns a collection of all values in the multimap. Changes to the returned collection will
   * update the underlying multimap, and vice versa.
   *

   * `new Integer` (as we do) instead of `Integer.valueOf`. However, under J2KT, `new Integer`
   * gets translated back to `Integer.valueOf` because that is the only thing J2KT can support. And
   * anyway, it's nice to avoid `Integer.valueOf` because the Android toolchain optimizes multiple
   * `Integer.valueOf` calls into one! So we stick with the deprecated `Integer` constructor.
   */

  public void testEqualsEquivalent() {