@Override
  public final void preTearDownCacheTestCase() throws Exception {
    xmlFile = null;
    GemFireCacheImpl.testCacheXml = null;

    waitForNoRebalancing();
    Invoke.invokeInEveryVM(CacheXmlTestCase::waitForNoRebalancing);

    if (previousMemoryEventTolerance != null) {
      System.setProperty(GeodeGlossary.GEMFIRE_PREFIX + "memoryEventTolerance",
          previousMemoryEventTolerance);
    }

    super.preTearDownCacheTestCase();
  }
set this to false if a test needs a non-loner distributed system
geode-dunit/src/main/java/org/apache/geode/cache30/CacheXmlTestCase.java