@Override
    public void beforeIndexLookup(Index index, int oper, Object key) {
      indexesUsed.add(index.getName());
    }
Validates a query result with client region values if region is not null, otherwise verifies
the size only.
geode-cq/src/distributedTest/java/org/apache/geode/cache/query/dunit/QueryIndexUpdateRIDUnitTest.java