public static void validateNoPoolCreation(final String siteId) {
    Set<GatewaySender> senders = cache.getGatewaySenders();
    for (GatewaySender sender : senders) {
      if (sender.getId().equals(siteId)) {
        AbstractGatewaySender sImpl = (AbstractGatewaySender) sender;
        assertNull(sImpl.getProxy());
      }
    }
  }
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