Edge edge34=graphModel.factory().newEdge(node3, node4, false);
Edge edge45=graphModel.factory().newEdge(node4, node5, false);
Edge edge56=graphModel.factory().newEdge(node5, node6, false);
Edge edge67=graphModel.factory().newEdge(node6, node7, false);
Edge edge72=graphModel.factory().newEdge(node7, node2, false);
undirectedGraph.addEdge(edge12);
undirectedGraph.addEdge(edge13);
undirectedGraph.addEdge(edge14);
undirectedGraph.addEdge(edge15);
undirectedGraph.addEdge(edge16);
undirectedGraph.addEdge(edge17);