compar uml element name ignor us name path tie breaker conveni compar simpl string us primari strength collat param model element param second model element java util compar compar java lang object java lang object compar object object equal collat compar model facad auml element string collat uml element model facad auml element string collat uml element element collat hope quick solut model facad model facad illeg argument except cast except model element requir comparison collat compar comparison comparison enclos path fulli distinguish compar path 