private int createLocator(VM vm, int dsid) {
    return vm.invoke(() -> {

      Properties properties = new Properties();
      properties.setProperty(ConfigurationProperties.DISTRIBUTED_SYSTEM_ID, Integer.toString(dsid));
      Locator locator = Locator.startLocatorAndDS(0, null, null);
      return locator.getPort();
    });
  }
Create the two sites (A and B) the client.

The client has two regions
- regionA = connected using poolA to serverA
- regionB = connected using poolB to serverB
geode-core/src/distributedTest/java/org/apache/geode/pdx/PdxMultiClusterClientServerDUnitTest.java