@Override
  public final void postSetUp() throws Exception {
    final Host host = Host.getHost(0);

    server1 = host.getVM(0);
    server1.invoke(ConflationDistributedTestHelper::unsetIsSlowStart);

    server2 = host.getVM(1);
    server2.invoke(ConflationDistributedTestHelper::unsetIsSlowStart);

    client1 = host.getVM(2);

    client2 = host.getVM(3);

    CacheObserverHolder.setInstance(new CacheObserverAdapter());
  }
This is the Dunit test to verify clear and destroyRegion operation in Client-Server
configuration.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/ha/HAClearDistributedTest.java