* A1----A2----A3
* \__A4
*
*/
Concern a1 = URNModelFactory.eINSTANCE.createConcern();
Concern a2 = URNModelFactory.eINSTANCE.createConcern();
Concern a3 = URNModelFactory.eINSTANCE.createConcern();
Concern a4 = URNModelFactory.eINSTANCE.createConcern();
accessLayer.addElement(project, a1);
accessLayer.addElement(project, a2);
accessLayer.addElement(project, a3);
accessLayer.addElement(project, a4);