overrid updat listen object old owner object owner set object listen hash set object collect set model element want listen owner todo call chang event model state flux ll invalid element except finish collect save grace call time time thing stabl ll good set element updat need better mechan add listen owner listen add object owner stereotyp todo aren stereotyp handl object stereotyp model facad stereotyp owner listen add object stereotyp featur object feat model facad featur owner listen add object feat stereotyp featur object stereotyp model facad stereotyp feat listen add object stereotyp paramet oper model facad oper feat object param model facad paramet feat listen add object param updat listen match desir set us minim updat facil updat element listen listen 