creat signal signal event target set signal event inherit doc action perform action event object target target manag instanc model target model facad signal event target model facad send action target model facad recept target model facad behavior featur target object sig model common behavior factori build signal target target manag instanc set target sig object ns model facad namespac target ns target ns model facad namespac target object element model common behavior factori creat signal target manag instanc set target element model core helper set namespac element ns action perform 