UnsupportedOperationException.class,
        () -> multimap().putAll(getSubjectGenerator().create(mapEntry(k3(), v3()))));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  // Empty multimaps *do* have defined equals semantics.
  @SuppressWarnings("UndefinedEquals")
  public void testPutAllIntoEmpty() {
    Multimap<K, V> target = getSubjectGenerator().create();
    assertEquals(!multimap().isEmpty(), target.putAll(multimap()));

    }
  }

  protected E[] createSamplesArray() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    getSampleElements().toArray(array);
    return array;
  }

  protected E[] createOrderedArray() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    getOrderedElements().toArray(array);
    return array;
  }

  public void testRemovingIteratorKnownOrder() {
    new IteratorTester<E>(
        4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

        .addEqualityGroup(multimap(), getSubjectGenerator().create(getSampleElements().toArray()))
        .testEquals();
  }

  public void testEqualsFalse() {
    List<Entry<K, V>> targetEntries = new ArrayList<>(getSampleElements());
    targetEntries.add(mapEntry(k0(), v3()));
    new EqualsTester()
        .addEqualityGroup(multimap())
        .addEqualityGroup(getSubjectGenerator().create(targetEntries.toArray()))

    }
  }

  protected E[] createSamplesArray() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    getSampleElements().toArray(array);
    return array;
  }

  protected E[] createOrderedArray() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    getOrderedElements().toArray(array);
    return array;
  }

   */
  public void testToArray_isPlainObjectArray() {
    Object[] array = collection.toArray();
    assertEquals(Object[].class, array.getClass());
  }

  public void testToArray_emptyArray() {
    E[] empty = getSubjectGenerator().createArray(0);
    E[] array = collection.toArray(empty);
    assertEquals(
        "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());

  protected void initMultimapWithNullKey() {
    resetContainer(getSubjectGenerator().create((Object[]) createArrayWithNullKey()));
  }

  protected void initMultimapWithNullValue() {
    resetContainer(getSubjectGenerator().create((Object[]) createArrayWithNullValue()));
  }

  protected void initMultimapWithNullKeyAndValue() {
    resetContainer(getSubjectGenerator().create((Object[]) createArrayWithNullKeyAndValue()));
  }

  public void testRemovingIteratorKnownOrder() {
    new IteratorTester<E>(
        4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

          parentBuilder) {
    // TODO(lowasser): make a SortedElementSetGenerator
    return SetTestSuiteBuilder.using(
            new ElementSetGenerator<E>(parentBuilder.getSubjectGenerator()))
        .named(getName() + ".elementSet")
        .withFeatures(computeElementSetFeatures(parentBuilder.getFeatures()))
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNull_supported() {
    E[] array = createArrayWithNullElement();
    collection = getSubjectGenerator().create(array);
    expectContents(array);
  }

  @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNull_unsupported() {