expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  public void testToArray_rightSizedArray() {
    E[] array = getSubjectGenerator().createArray(getNumElements());
    assertSame(
        "toArray(sameSizeE[]) should return the given array", array, collection.toArray(array));
    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  @CollectionFeature.Require(KNOWN_ORDER)

  public void testRetainAll_duplicatesKept() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);
    assertFalse(
        "containsDuplicates.retainAll(superset) should return false",
        collection.retainAll(MinimalCollection.of(createSamplesArray())));
    expectContents(array);
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    return multimap;
  }

  /**
   * @return an array of the proper size with {@code null} as the key of the middle element.
   */
  protected Entry<K, V>[] createArrayWithNullKey() {
    Entry<K, V>[] array = createSamplesArray();
    int nullKeyLocation = getNullLocation();
    Entry<K, V> oldEntry = array[nullKeyLocation];
    array[nullKeyLocation] = mapEntry(null, oldEntry.getValue());
    return array;
  }

  /**

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);

    expectContents(array);
  }

  }

  @ListFeature.Require(SUPPORTS_SET)
  public void testReplaceAll_changesSome() {
    getList().replaceAll(e -> e.equals(samples.e0()) ? samples.e3() : e);
    E[] expected = createSamplesArray();
    for (int i = 0; i < expected.length; i++) {
      if (expected[i].equals(samples.e0())) {
        expected[i] = samples.e3();
      }
    }
    expectContents(expected);
  }

  }

  @MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testCreateWithNullKeyAndValueSupported() {
    Entry<K, V>[] entries = createSamplesArray();
    entries[getNullLocation()] = entry(null, null);
    resetMap(entries);
    expectContents(entries);
  }

  @MapFeature.Require(value = ALLOWS_NULL_KEYS, absent = REJECTS_DUPLICATES_AT_CREATION)

  }

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nonNullDuplicatesNotRejected() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);

    List<E> expectedWithDuplicateRemoved = asList(array).subList(1, getNumElements());
    expectContents(expectedWithDuplicateRemoved);

  }

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nonNullDuplicatesNotRejected() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);

    List<E> expectedWithDuplicateRemoved = asList(array).subList(1, getNumElements());
    expectContents(expectedWithDuplicateRemoved);

    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());
    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testSubList_subListClearAffectsOriginal() {
    List<E> subList = getList().subList(0, 1);
    subList.clear();
    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());

    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());
    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testSubList_subListClearAffectsOriginal() {
    List<E> subList = getList().subList(0, 1);
    subList.clear();
    List<E> expected = asList(createSamplesArray()).subList(1, getNumElements());