public Map<String, String> listThreadsHoldingLock() {
    Iterator<LockServiceMXBean> it = mapOfProxy.values().iterator();
    threadsHoldingLock.clear();
    if (it != null) {
      while (it.hasNext()) {
        Map<String, String> threadLockMap = it.next().listThreadsHoldingLock();
        if (threadLockMap != null) {
          threadsHoldingLock.putAll(threadLockMap);
        }


      }

    }
    return threadsHoldingLock;
  }
@return a map of object name and thread name if this member holds lock or null/none
geode-core/src/main/java/org/apache/geode/management/internal/beans/DistributedLockServiceBridge.java