parent2.put("name", "name_parent2");
Node child1 = ds.addNode(1);
child1.put("type", "type1");
parent1.addMember(new RelationMember("", child1));
parent2.addMember(new RelationMember("", child1));
Node child2 = ds.addNode(2);
child2.put("type", "type2");
parent1.addMember(new RelationMember("", child2));
parent2.addMember(new RelationMember("", child2));
Relation grandParent = ds.addRelation(3);
grandParent.put("type", "grandparent");