@Override
  public DistributedSystemMXBean getDistributedSystemMXBean() {
    return getMBeanProxy(MBeanJMXAdapter.getDistributedSystemName(), DistributedSystemMXBean.class);
  }
Gets a proxy to the remote DistributedSystem MXBean to access attributes and invoke operations
on the distributed system, or the GemFire cluster.

@return a proxy instance of the GemFire Manager's DistributedSystem MXBean.
@see #getMBeanProxy(javax.management.ObjectName, Class)
geode-gfsh/src/main/java/org/apache/geode/management/internal/web/shell/HttpOperationInvoker.java