stimulu build stimulu object link link link model impl core helper sourc link model impl core helper destin link stimulu stimulu creat stimulu object sender model impl core helper sourc link object receiv model impl core helper destin link model impl common behavior helper set receiv stimulu receiv model impl collabor helper set sender stimulu sender model impl common behavior helper set commun link stimulu link stimulu illeg argument except argument link doe sourc destin instanc 