edg go given port read model element param port model element queri list incom connect list edg object port list object edg arrai list object hierarchi model facad model element port iter model facad supplier depend port iter edg add generaliz element model facad generaliz element port iter model facad special port iter edg add classifi model facad classifi port model facad port iter model facad associ end port iter object assoc end navig want incom model facad navig assoc end edg add assoc end model facad instanc port iter model facad link end port iter edg add edg 