@Test
  public void testShutdown() throws Exception {
    AmbryQuotaManager ambryQuotaManager = buildAmbryQuotaManagerWithAmbryCUEnforcer();

    // 1. test that shutdown doesn't do anything if init isn't called yet.
    ambryQuotaManager.shutdown();
    Assert.assertEquals(0, testAmbryCUQuotaEnforcer.shutdownCallCount);

    // 2. test that shutdown works after init.
    ambryQuotaManager.init();
    ambryQuotaManager.shutdown();
    Assert.assertEquals(1, testAmbryCUQuotaEnforcer.shutdownCallCount);

    // 3. test that repeated call of shutdown doesn't do anything.
    ambryQuotaManager.shutdown();
    Assert.assertEquals(1, testAmbryCUQuotaEnforcer.shutdownCallCount);
  }
Running for both {@link AmbryQuotaManager} as well as {@link AtomicAmbryQuotaManager}.
@return an array container a flag that is {@code true} for {@link AtomicAmbryQuotaManager} and {@code false} for
{@link AmbryQuotaManager}.
ambry-quota/src/test/java/com/github/ambry/quota/AmbryQuotaManagerTest.java