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

        for (int i = 0; i < 10; i++) {
            final boolean added = set.add(i);
            assertTrue("Element " + i + " should be added", added);
        }
    }