@Override
    public void beforeIterationEvaluation(CompiledValue executer, Object currentObject) {
      if (currentObject instanceof VMCachedDeserializable) {
        getLogWriter().fine("currentObject is serialized object");
        isObjectSerialized = true;
      } else {
        getLogWriter().fine("currentObject is deserialized object");
      }
    }
Used for saving & restoring oldObserver without serialization
geode-core/src/distributedTest/java/org/apache/geode/cache/query/dunit/SelectStarQueryDUnitTest.java