private static void closeCache() {
    GemFireCacheImpl cache = GemFireCacheImpl.getInstance();
    if (cache != null && !cache.isClosed()) {
      destroyRegions(cache);
      cache.close();
    }
  }
{@code postTearDown()} is invoked after {@link #doTearDownDistributedTestCase()}.

<p>
Override this as needed. Default implementation is empty.
geode-dunit/src/main/java/org/apache/geode/test/dunit/internal/JUnit4DistributedTestCase.java