docs: public void stopDeletingMsgsWihoutReferencesTask(boolean hasToStop) {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(tc, "stopDeletingMsgsWihoutReferencesTask", hasToStop);
  
          if (null != _pubsubMessageItemStream) {
              //signal so that PubSubMessageItemStream's deleteMsgsWithNoReferences() greacefully exits
              _pubsubMessageItemStream.stopDeletingMsgsWihoutReferencesTask(hasToStop);
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(tc, "stopDeletingMsgsWihoutReferencesTask", hasToStop);
  
      }