code: private void tagSubtypesAsAffectedByReload() {
  		if (associatedSubtypes != null) {
  			for (Reference<ReloadableType> ref : associatedSubtypes) {
  				ReloadableType rsubtype = ref.get();
  				if (rsubtype != null) {
  					rsubtype.tagAsAffectedByReload();
  					rsubtype.tagSubtypesAsAffectedByReload();
  				}
  			}
  		}
  	}
docs: TODO who is clearing up dead entries?