@Test
  public void testPersistAndOverflowAndThenOverflowOnly() {
    createPersistAndOverflow();
    put100Int();
    region.close();
    try {
      createOverflowOnly();
      fail("expected IllegalStateException");
    } catch (IllegalStateException ignored) {
    }
    createPersistAndOverflow();
  }
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