@Override
      public void afterUpdate2(EntryEvent event) {
        assertEquals(null, event.getOldValue());
        assertEquals(false, event.isOldValueAvailable());
      }
Tests cache listeners in an overflow region are invoked and that their events are reasonable.
geode-core/src/integrationTest/java/org/apache/geode/cache30/DiskRegionIntegrationTest.java