@Test
  public void testGatewaySenderEventListenerPoolImpl() {
    Integer lnPort = vm0.invoke(() -> WANTestBase.createFirstLocatorWithDSId(1));
    Integer nyPort = vm1.invoke(() -> WANTestBase.createFirstRemoteLocator(2, lnPort));

    createCacheInVMs(nyPort, vm2, vm3);
    createReceiverInVMs(vm2, vm3);

    createCacheInVMs(lnPort, vm4);

    vm4.invoke(() -> WANTestBase.createSenderWithListener("ln", 2, false, 100, 10, false, false,
        null, false, false));

    vm4.invoke(() -> SerialGatewaySenderEventListenerDUnitTest.validateNoPoolCreation("ln"));
  }
Test validates whether the PoolImpl is created. Ideally when a listener is attached pool should
not be created.
geode-wan/src/distributedTest/java/org/apache/geode/internal/cache/wan/serial/SerialGatewaySenderEventListenerDUnitTest.java