@Before
  public void before() throws Exception {
    disconnectAllFromDS();

    mcastPort = getRandomAvailableUDPPort();
    locatorPort = getRandomAvailableTCPPort();
    tcpPort = getRandomAvailableTCPPort();

    int[] portRange = getRandomAvailableTCPPortRange(3);
    lowerBoundOfPortRange = portRange[0];
    upperBoundOfPortRange = portRange[portRange.length - 1];
  }
Tests the functionality of the {@link DistributedSystem} class.
geode-core/src/distributedTest/java/org/apache/geode/distributed/DistributedSystemDUnitTest.java