@Override
        public String description() {
          return "Waiting for all sites to get updated, the sizes are " + listenerMap.size()
              + " and " + map.size();
        }
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