@Override
    public boolean add(E element) {
        return add(element, element.hashCode());
    }
@Test
    public void testContainsAll() {
        final OAHashSet<Integer> set = new OAHashSet<>(8);
        populateSet(set, 10);

        Collection<Integer> elementsToCheck = new ArrayList<>(10);
        for (int i = 0; i < 10; i++) {
            elementsToCheck.add(i);
        }

        final boolean containedAll = set.containsAll(elementsToCheck);
        assertTrue("All elements should be contained", containedAll);
    }