@Test
  public void testPersistOnlyAndThenPeristAndOverflow() {
    createPersistOnly();
    put100Int();
    region.close();
    createPersistAndOverflow();
    assertTrue(region.size() == 100);
  }
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