usag build usag object client object supplier client supplier illeg argument except build usag argument client model element illeg argument except client model element supplier model element illeg argument except supplier model element todo uml spec requir client supplier model tfm usag usag creat usag usag supplier add model element supplier usag client add model element client model element supplier namespac usag set namespac model element supplier namespac model element client namespac usag set namespac model element client namespac todo add standard stereotyp set open end predefin name includ creat instanti send usag 