code: public void registerEventCallback(ObjectManagerEventCallback callback)
      {
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.entry(this, cclass, "registerEventCallback", callback);
  
          objectManagerState.registerEventCallback(callback);
  
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.exit(this, cclass, "registerEventCallback");
      }
docs: Defect 495856, 496893