TreeStructure treeStructure = dhns.getGraphStructure().getMainView().getStructure();
GraphFactoryImpl factory = dhns.factory();
Node node1 = factory.newNode();
Node node2 = factory.newNode();
graph.addNode(node1);
graph.addNode(node2);
AbstractEdge edge1 = factory.newEdge(node1, node2, 3f, true);
graph.addEdge(edge1);
AbstractEdge edge2 = factory.newEdge(node2, node1, 1f, true);