creat edg given type connect given node param graph model graph model contain object param edg type uml object type connect param element fig element param dest fig node fig element newli creat fig edg fig edg build connect mutabl graph model graph model object edg type fig element fig dest fig node object model element graph model connect element owner dest fig node owner edg type set edg model element call connect add edg graph model layer persect graph model edg ad event add appropri fig edg determin graph edg render edg sourc fig node damag dest fig node damag layer lai editor layer manag activ layer fig edg fe fig edg lai present edg item set line color color black fe set fig item fe set sourc port fig start port fig fe set sourc fig node sourc fig node fe set dest port fig dest fig node fe set dest fig node fig node dest fig node fe 