@Test
public void testTwoRelationExistingCircular() {
DataSet source = new DataSet();
Relation r1 = new Relation(1, 1);
source.addPrimitive(r1);
Relation r2 = new Relation(2, 3);
source.addPrimitive(r2);
r1.addMember(new RelationMember("relation-2",r2));
r2.addMember(new RelationMember("relation-1",r1));
source.setSelected(r1,r2);