@Override
      public Object call() {
        TXManagerImpl mgr = getGemfireCache().getTxManager();
        Region<OrderId, Order> orderRegion = getCache().getRegion(ORDER);
        mgr.begin();
        CustId custId = new CustId(1);
        OrderId orderId = new OrderId(1000, custId);
        Order expectedOrder = new Order("fooOrder");
        Map map = new HashMap();
        map.put(orderId, expectedOrder);
        orderRegion.putAll(map);
        mgr.rollback();
        assertNull(orderRegion.get(orderId));
        return null;
      }
Tests the basic client-server transaction functionality
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ClientServerTransactionDUnitTest.java