@Override
      public Object call() throws Exception {
        if (TestRegion.getTombstoneCount() == 0) {
          LogWriterUtils.getLogWriter().warning("region has no tombstones");
          // TestRegion.dumpBackingMap();
          throw new AssertionError("expected to find tombstones but region is empty");
        }
        return null;
      }
test that distributed GC messages are properly cleaned out of durable client HA queues
geode-core/src/distributedTest/java/org/apache/geode/cache30/ClientServerCCEDUnitTest.java