CachingAvatarZooKeeperClient cazkc = new CachingAvatarZooKeeperClient(conf, null);
Method m = CachingAvatarZooKeeperClient.class.getDeclaredMethod(
"tryLock", ZooKeeperCall.class);
ZooKeeperCall call = cazkc.new GetStat(null);
m.setAccessible(true);
FileWithLock fl = (FileWithLock) m.invoke(cazkc, call);
fl.lock.release();
TestCase.assertNotNull(fl.lock);
fl = (FileWithLock) m.invoke(cazkc, call);
TestCase.assertNotNull(fl.lock);
fl.lock.release();