@Override
    public void afterRegionDestroy(RegionEvent revt) {
      // fail("Unexpected listener callback: afterRegionDestroy");
    }
is called when a region is destroyed.

@param revt a RegionEvent to represent the source region.
@throws CacheException if any error occurs.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/SystemFailureDUnitTest.java