}

  @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() {
    E[] array = createSamplesArray();
    array[1] = e0();
    collection = getSubjectGenerator().create(array);

    expectContents(array);
  }

    assertEquals(
        Platform.format("remove(%d) should return the element at index %d", index, index),
        getList().get(index),
        getList().remove(index));
    List<E> expected = copyToList(createSamplesArray());
    expected.remove(index);
    expectContents(expected);
  }

    return "indexOf";
  }

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "indexOf(duplicate) should return index of first occurrence", 0, getList().indexOf(e0()));
  }

  @CollectionFeature.Require(absent = KNOWN_ORDER)
  public void testForEachUnknownOrder() {
    List<E> elements = new ArrayList<>();
    collection.forEach(elements::add);
    assertEqualIgnoringOrder(asList(createSamplesArray()), elements);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testForEachKnownOrder() {
    List<E> elements = new ArrayList<>();
    collection.forEach(elements::add);

    return "lastIndexOf";
  }

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testLastIndexOf_duplicate() {
    E[] array = createSamplesArray();
    array[getNumElements() / 2] = e0();
    collection = getSubjectGenerator().create(array);
    assertEquals(
        "lastIndexOf(duplicate) should return index of last occurrence",
        getNumElements() / 2,

    }
  }

  /**
   * @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] = entry(null, oldEntry.getValue());
    return 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);
  }

    }
  }

  /**
   * @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] = entry(null, oldEntry.getValue());
    return array;
  }

   */
  protected void expectMissing(E... elements) {
    for (E element : elements) {
      assertFalse("Should not contain " + element, actualContents().contains(element));
    }
  }

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

  protected E[] createOrderedArray() {