@Override
    public void onEvent(CqEvent cqEvent) {
      if (cqEvent.getQueryOperation() == Operation.DESTROY) {
        return;
      }

      K key = cast(cqEvent.getKey());
      V newValue = cast(cqEvent.getNewValue());

      if (newValue == null) {
        region.create(key, null);
      } else {
        region.put(key, newValue);
        updates.incrementAndGet();
      }
    }
Defines an action to be run after the specified operation is invoked by Geode callbacks.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/PutAllClientServerDistributedTest.java