@Override
  public DistributionConfig getConfig() {
    DistributionConfig result = null;
    InternalDistributedSystem sys = getSystem();
    if (sys != null) {
      result = system.getConfig();
    }
    return result;
  }
Returns true if this distribution manager has been closed.
geode-core/src/main/java/org/apache/geode/distributed/internal/ClusterDistributionManager.java