@Test
public void testAddUsage() {

    List<ACL> testACL = createACL("myid");
    ReferenceCountedACLCache cache = new ReferenceCountedACLCache();
    Long aclId = cache.convertAcls(testACL);
    assertEquals(1, cache.size());
    cache.addUsage(aclId);
    assertEquals(1, cache.size());
    cache.removeUsage(aclId);
    assertEquals(1, cache.size());
    cache.removeUsage(aclId);
    assertEquals(0, cache.size());
}