rom: 10, to: 9}
  ];

  // create a network
  var container = document.getElementById('mynetwork');
  var data = {
    nodes: nodes,
    edges: edges
  };
  var options = {layout:{randomSeed:8}};
  var network = new vis.Network(container, data, options);
  network.on("selectNode", function(params) {
      if (params.nodes.length == 1) {
          if (network.isCluster(params.nodes[0]) == true) {
              network.openCluster(params.nodes[0]);
          }
      }
  });

  function clusterByCid() {
      