code: void invalidate()
      {
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.entry(this, cclass
                          , "invalidate"
                              );
  
          // Prevent any attempt to load the object.
          objectStore = null;
  
          // If the ManagedObject is already in memory access it, otherwise there is nothing
          // we need to do to it.
          if (managedObjectReference != null) {
              ManagedObject managedObject = (ManagedObject) managedObjectReference.get();
              if (managedObject != null)
                  managedObject.state = ManagedObject.stateError;
          } // if (managedObjectReference != null).
  
          if (Tracing.isAnyTracingEnabled() && trace.isEntryEnabled())
              trace.exit(this, cclass
                         , "invalidate"
                              );
      }
docs: Make the token and any ManagedObject it refers to invalid.
  Used at shutdown to prevent accidental use of a ManagedObject in the ObjectManager that
  instantiated it or any other Object Manager.