public void testStreamToArrayUnknownOrder() {
    Helpers.assertEqualIgnoringOrder(getSampleElements(), asList(collection.stream().toArray()));
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testStreamToArrayKnownOrder() {
    assertEquals(getOrderedElements(), asList(collection.stream().toArray()));
  }

  public void testStreamCount() {
    assertEquals(getNumElements(), collection.stream().count());
  }