static InternalDistributedSystem getConnectedDistributedSystem(Properties properties) {
    if (system == null || !system.isConnected()) {
      properties.setProperty(NAME, "vm" + VM.getCurrentVMNum());
      system = (InternalDistributedSystem) DistributedSystem.connect(properties);
    }
    return system;
  }
a locator is restarted twice with a server and ends up in a split-brain
geode-core/src/distributedTest/java/org/apache/geode/distributed/LocatorDUnitTest.java