set extens point object handl collect extens point handl us handl extend illeg argument except extens point illeg argument except object extens point extens point illeg argument except runnabl run runnabl run handl extend extend handl extens locat clear object extens point extend handl extens locat add extens point handl us us handl extens point clear object extens point us handl extens point add extens point model impl edit domain command stack execut chang command model impl run set extens point extens point size handl 