### Question:
ThrottleUtil { public static int esClusterDesc(String host) { String key = THROTTLE_KEY_ESCLUSTER + host; AtomicInteger counter = getCounter(key); return counter.decrementAndGet(); }  static int esClusterInc(String host); static int esClusterDesc(String host);  }### Answer:
@Test public void testEsClusterDesc () { ThrottleUtil.esClusterInc("test_cluster2"); ThrottleUtil.esClusterInc("test_cluster2"); ThrottleUtil.esClusterDesc("test_cluster2"); AtomicInteger c = ThrottleUtil.getCounter("cluster:test_cluster2"); assertEquals(1, c.get()); }