sameElements = new Target(asList(createSamplesArray()), "sameElements");
    containsDuplicates =
        new Target(MinimalCollection.of(e0(), e0(), e3(), e3()), "containsDuplicates");
    partialOverlap = new Target(MinimalCollection.of(e2(), e3()), "partialOverlap");
    nullSingleton = new Target(Collections.<E>singleton(null), "nullSingleton");
  }

  // retainAll(empty)

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    sameElements = new Target(asList(createSamplesArray()), "sameElements");
    containsDuplicates =
        new Target(MinimalCollection.of(e0(), e0(), e3(), e3()), "containsDuplicates");
    partialOverlap = new Target(MinimalCollection.of(e2(), e3()), "partialOverlap");
    nullSingleton = new Target(Collections.<E>singleton(null), "nullSingleton");
  }

  // retainAll(empty)

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(
        "containsAll(partialOverlap) should return false",
        collection.containsAll(MinimalCollection.of(e0(), e3())));
  }

  public void testContainsAll_disjoint() {
    assertFalse(
        "containsAll(disjoint) should return false",

    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(
        "containsAll(partialOverlap) should return false",
        collection.containsAll(MinimalCollection.of(e0(), e3())));
  }

  public void testContainsAll_disjoint() {
    assertFalse(
        "containsAll(disjoint) should return false",