@Test // serial, ReplicateRegion, RegressionTest
  public void testConcurrentSerialAsyncEventQueueWithoutOrderPolicy() {
    vm0.invoke(this::createCache);
    vm1.invoke(this::createCache);
    vm2.invoke(this::createCache);

    vm0.invoke(() -> createConcurrentAsyncEventQueue(asyncEventQueueId, new SpyAsyncEventListener(),
        true, 100, 3, 100, null, false));
    vm1.invoke(() -> createConcurrentAsyncEventQueue(asyncEventQueueId, new SpyAsyncEventListener(),
        true, 100, 3, 100, null, false));
    vm2.invoke(() -> createConcurrentAsyncEventQueue(asyncEventQueueId, new SpyAsyncEventListener(),
        true, 100, 3, 100, null, false));

    vm0.invoke(() -> createReplicateRegion(replicateRegionName, asyncEventQueueId));
    vm1.invoke(() -> createReplicateRegion(replicateRegionName, asyncEventQueueId));
    vm2.invoke(() -> createReplicateRegion(replicateRegionName, asyncEventQueueId));

    vm0.invoke(() -> doPuts(replicateRegionName, 1000));

    // primary sender
    vm0.invoke(() -> validateAsyncEventListener(1000));

    // secondaries
    vm1.invoke(() -> validateAsyncEventListener(0));
    vm2.invoke(() -> validateAsyncEventListener(0));
  }
Dispatcher threads set to more than 1 but no order policy set.

<p>
Regression test for TRAC #50514: NullPointerException in AsyncEventListener if adding
AsyncEventQueue with using API and setting number of dispatchers more than 1
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/wan/asyncqueue/ConcurrentAsyncEventListenerDistributedTest.java