@Test
  public void testSerialGatewaySender() throws Exception {
    getSystem();
    CacheCreation cache = new CacheCreation();
    DiskStoreFactory dsf = cache.createDiskStoreFactory();
    dsf.create("LNSender");

    GatewaySenderFactory gatewaySenderFactory = cache.createGatewaySenderFactory();
    gatewaySenderFactory.setParallel(false);
    gatewaySenderFactory.setManualStart(true);
    gatewaySenderFactory.setSocketBufferSize(124);
    gatewaySenderFactory.setSocketReadTimeout(1000);
    gatewaySenderFactory.setBatchConflationEnabled(false);
    gatewaySenderFactory.setBatchSize(100);
    gatewaySenderFactory.setBatchTimeInterval(10);
    gatewaySenderFactory.setPersistenceEnabled(true);
    gatewaySenderFactory.setDiskStoreName("LNSender");
    gatewaySenderFactory.setDiskSynchronous(true);
    gatewaySenderFactory.setMaximumQueueMemory(200);
    gatewaySenderFactory.setAlertThreshold(30);

    GatewayEventFilter myEventFilter1 = new MyGatewayEventFilter1();
    gatewaySenderFactory.addGatewayEventFilter(myEventFilter1);
    GatewayTransportFilter myStreamFilter1 = new MyGatewayTransportFilter1();
    gatewaySenderFactory.addGatewayTransportFilter(myStreamFilter1);
    GatewayTransportFilter myStreamFilter2 = new MyGatewayTransportFilter2();
    gatewaySenderFactory.addGatewayTransportFilter(myStreamFilter2);
    GatewaySender serialGatewaySender = gatewaySenderFactory.create("LN", 2);

    RegionAttributesCreation attrs = new RegionAttributesCreation();
    attrs.addGatewaySenderId(serialGatewaySender.getId());
    cache.createRegion("UserRegion", attrs);

    testXml(cache);
    Cache c = getCache();
    assertNotNull(c);
    Set<GatewaySender> sendersOnCache = c.getGatewaySenders();
    for (GatewaySender sender : sendersOnCache) {
      assertEquals(false, sender.isParallel());
      validateGatewaySender(serialGatewaySender, sender);
    }
  }
Added to test the scenario of defect #50600.
geode-wan/src/distributedTest/java/org/apache/geode/cache/CacheXml70GatewayDUnitTest.java