docs: @Override
      public void announceMPStopping()
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(tc, "announceMPStopping");
  
          if (isPubSub()) {
              if (null != _pubSubRealization) { //doing a sanity check with checking for not null
                  //signal to _pubSubRealization to gracefully exit from deleteMsgsWithNoReferences()
                  _pubSubRealization.stopDeletingMsgsWihoutReferencesTask(true);
              }
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(tc, "announceMPStopping");
      }