// build graph for test case
Goal g1 = createGoal(gss, 1);
Principle p1 =createPrinciple(gss, 1);
Pattern si1 = createPattern(gss, 1);
Offset offset = GSSFactory.eINSTANCE.createOffset();
offset.setSource(si1);
offset.setTarget(g1);
offset.setValue(null);
createImpact(gss, si1, p1, 20);
createImpact(gss, p1, g1, 20);
gss.getRelations().add(offset);