@Test
  public void testBasicClose() {
    {
      forceDeleteFiles();
      try {
        region = DiskRegionHelperFactory.getAsyncOverFlowAndPersistRegion(cache, diskProps);
      } catch (Exception e) {
        logWriter.error("Exception occurred", e);
        fail(" Exception in createOverflowandPersist due to " + e);
      }
      region.close();
      closeDiskStores();
      checkIfContainsFileWithExt("lk");
    }
    {
      forceDeleteFiles();
      try {
        region = DiskRegionHelperFactory.getAsyncOverFlowOnlyRegion(cache, diskProps);
      } catch (Exception e) {
        logWriter.error("Exception occurred", e);
        fail(" Exception in createOverflowOnly due to " + e);
      }
      region.close();
      closeDiskStores();
      checkIfContainsFileWithExt("lk");
    }
    {
      forceDeleteFiles();
      try {
        region = DiskRegionHelperFactory.getAsyncPersistOnlyRegion(cache, diskProps);
      } catch (Exception e) {
        logWriter.error("Exception occurred", e);
        fail(" Exception in createOverflowandPersist due to " + e);
      }
      region.close();
      closeDiskStores();
      checkIfContainsFileWithExt("lk");
    }
    // Asif: Recreate the region so that it will be destroyed
    try {
      region = DiskRegionHelperFactory.getAsyncPersistOnlyRegion(cache, diskProps);
    } catch (Exception e) {
      logWriter.error("Exception occurred", e);
      fail(" Exception in createOverflowandPersist due to " + e);
    }

  }
Testing methods for SimpleDiskRegion.java api's

@since GemFire 5.1
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/SimpleDiskRegionJUnitTest.java