private static void verifyQueueData(Integer port) {
    // Get the clientMessagesRegion and check the size.
    Region<Object, Object> msgsRegion =
        cache.getRegion(CacheServerImpl.generateNameForClientMsgsRegion(port));
    Region region = cache.getRegion(SEPARATOR + regionName);
    logger.debug(
        "size<serverRegion, clientMsgsRegion>: " + region.size() + ", " + msgsRegion.size());
    assertThat(region.size()).isEqualTo(((Integer) 5).intValue());
    assertThat(msgsRegion.size()).isEqualTo(((Integer) 5).intValue());

    for (Object o : msgsRegion.entrySet()) {
      await().untilAsserted(() -> {
        Entry entry = (Entry) o;
        HAEventWrapper wrapper = (HAEventWrapper) entry.getKey();
        ClientUpdateMessage cum = (ClientUpdateMessage) entry.getValue();
        Object key = cum.getKeyOfInterest();
        logger.debug("key<feedCount, regionCount>: " + key + "<"
            + map.get(key) + ", " + wrapper.getReferenceCount() + ">");
        assertThat(wrapper.getReferenceCount()).isEqualTo(((Long) map.get(key)).longValue());
      });
    }
  }
This test verifies that the memory footprint of the ha region queues is less when ha-overflow
is enabled (with an appropriate value of haCapacity) compared to when it is disabled, for the
same amount of data feed.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ha/HARQueueNewImplDistributedTest.java