@Override
    public boolean contains(long value) {
        assert value != nullValue : "contains() called with null-sentinel value " + nullValue;
        return hsa.get(value) != NULL_ADDRESS;
    }
@Test
    public void testContains() {
        long key = random.nextLong();
        assertFalse(set.contains(key));
        set.add(key);
        assertTrue(set.contains(key));
    }