undirectedGraph.addNode(node2);
undirectedGraph.addNode(node3);
undirectedGraph.addNode(node4);
undirectedGraph.addNode(node5);
undirectedGraph.addNode(node6);
undirectedGraph.addNode(node7);
Edge edge12=graphModel.factory().newEdge(node1, node2, false);
Edge edge13=graphModel.factory().newEdge(node1, node3, false);
Edge edge14=graphModel.factory().newEdge(node1, node4, false);
Edge edge15=graphModel.factory().newEdge(node1, node5, false);
Edge edge16=graphModel.factory().newEdge(node1, node6, false);