@Override
      public void run2() throws CacheException {
        Region region = getRootRegion().getSubregion(regionName);
        logger.info("### Entries in Client :" + region.keySet().size());
      }
Tests execution of queries with NULL in where clause like where ID = NULL etc.
geode-cq/src/distributedTest/java/org/apache/geode/cache/query/cq/dunit/CqQueryDUnitTest.java