@Override
    public void clear() {
        repo.clear();
    }
@Test
    public void testClear() throws Exception {
        // ADD key to remove
        assertTrue(repo.add(key01));
        assertEquals(1, cache.size());

        // remove key
        assertTrue(repo.remove(key01));
        assertEquals(0, cache.size());

        // try to remove a key that isn't there
        assertFalse(repo.remove(key02));
    }