code: @Override
      public synchronized void persistableOperationBegun() throws SevereMessageStoreException
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "persistableOperationBegun");
  
          _persistableOperationBegunCounter++;
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEventEnabled())
              SibTr.event(this, tc, "persistableOperationBegunCounter: " + _persistableOperationBegunCounter);
  
          if (_link != null)
          {
              if (_persistableOperationBegunCounter - _persistableOperationCompletedCounter == 1)
              {
                  _link.persistentRepresentationIsUnstable();
              }
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "persistableOperationBegun");
      }
docs: **********************************************************************