private Region createOverflowPR(Cache cache, String diskStoreName) {
    RegionFactory rf = cache.createRegionFactory();
    rf.setDataPolicy(DataPolicy.PARTITION);
    rf.setEvictionAttributes(
        EvictionAttributes.createLRUEntryAttributes(1, EvictionAction.OVERFLOW_TO_DISK));
    rf.setPartitionAttributes(new PartitionAttributesFactory().setTotalNumBuckets(1).create());
    rf.setDiskStoreName(diskStoreName);
    return rf.create(name.getMethodName());
  }
Test for transactional operations on overflowed data
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/eviction/TransactionsWithOverflowTest.java