@Override
  public Properties getDistributedSystemProperties() {
    if (properties == null) {
      properties = new Properties();
      properties.put(ConfigurationProperties.ENABLE_NETWORK_PARTITION_DETECTION, "false");
    }
    return properties;
  }
Starts up 4 server and the controller vm as a client, then calls and tests
ClientMembership.getConnectedServers().
geode-core/src/distributedTest/java/org/apache/geode/cache30/ClientMembershipDUnitTest.java