@CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRemove_duplicate() {
    ArrayWithDuplicate<E> arrayAndDuplicate = createArrayWithDuplicateElement();
    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    int firstIndex = getList().indexOf(duplicate);

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRemoveAll_duplicate() {
    ArrayWithDuplicate<E> arrayAndDuplicate = createArrayWithDuplicateElement();
    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRemoveAll_duplicate() {
    ArrayWithDuplicate<E> arrayAndDuplicate = createArrayWithDuplicateElement();
    collection = getSubjectGenerator().create(arrayAndDuplicate.elements);
    E duplicate = arrayAndDuplicate.duplicate;

    assertTrue(
        "removeAll(intersectingCollection) should return true",

      this.duplicate = duplicate;
    }
  }

  /**
   * @return an array of the proper size with a duplicate element. The size must be at least three.
   */
  protected ArrayWithDuplicate<E> createArrayWithDuplicateElement() {
    E[] elements = createSamplesArray();
    E duplicate = elements[(elements.length / 2) - 1];
    elements[(elements.length / 2) + 1] = duplicate;
    return new ArrayWithDuplicate<>(elements, duplicate);