private void createRegionAndServer(VM vm, final int port) {
    vm.invoke(new SerializableCallable() {
      @Override
      public Object call() throws Exception {
        getCache().createRegionFactory(RegionShortcut.REPLICATE).create("region");
        Cache cache = getCache();
        CacheServer server = cache.addCacheServer();
        server.setPort(port);
        server.start();
        return null;
      }
    });

  }
A simple test case that we are actually persisting with a PR.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/InterruptClientServerDUnitTest.java