public void testContainsAll_subset() {
    assertTrue(
        "containsAll(subset) should return true",
        collection.containsAll(MinimalCollection.of(e0())));
  }

  public void testContainsAll_sameElements() {
    assertTrue(
        "containsAll(sameElements) should return true",
        collection.containsAll(MinimalCollection.of(createSamplesArray())));
  }

  @SuppressWarnings("ModifyingCollectionWithItself")