handl fig move compon param enclos enclos fig compon fig enclos object compon enclos owner object owner owner model facad compon compon model facad auml element owner collect er model facad element resid owner collect er model facad resid element compon element resid compon collect object common arrai list object er common retain er object element resid common correct element resid element resid strang model uml factori delet element resid element resid let creat model core factori build element resid owner compon 