@Override
  public final void postSetUp() throws Exception {
    host = Host.getHost(0);
    server1 = host.getVM(0);
    server2 = host.getVM(1);
    client1 = host.getVM(2);
    client2 = host.getVM(3);
  }
Tests behaviour of transactions in client server model
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/CacheServerTransactionsDUnitTest.java