@Test
  public void testGetParentRegion() throws CacheException {
    if (!supportsSubregions()) {
      return;
    }
    String name = getUniqueName();

    Region<Object, Object> region = createRegion(name);
    assertEquals(getRootRegion(), region.getParentRegion());

    RegionFactory<Object, Object> regionFactory = cache.createRegionFactory(region.getAttributes());
    Region sub = regionFactory.createSubregion(region, "SUB");
    assertEquals(region, sub.getParentRegion());
    assertSame(sub, region.getSubregion("SUB"));
    assertNotNull(sub.getAttributes());
  }
Tests the {@link Region#getParentRegion} method
geode-dunit/src/main/java/org/apache/geode/cache30/RegionTestCase.java