private void createOverflowOnly() {
    props.setOverFlowCapacity(1);
    region = DiskRegionHelperFactory.getSyncOverFlowOnlyRegion(cache, props);
  }
This test will test that there are no unexpected behaviours if the the region attributes are
changed after starting it again.

The behaviour should be predictable
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/DiskRegionChangingRegionAttributesJUnitTest.java