@Override
      public Object call() {
        for (Object key : keys) {
          assertTrue("expected to find a tombstone for " + key, TestRegion.containsTombstone(key));
        }
        return null;
      }
test that clients receive tombstones in register-interest results
geode-core/src/distributedTest/java/org/apache/geode/cache30/ClientServerCCEDUnitTest.java