bind('fromPortId', 'fromport')
      .add(
        new go.Shape({ stroke: 'lightblue', strokeWidth: 2 }) // the link shape
      );

    // create the model for the decision tree
    var model = new go.GraphLinksModel({ linkFromPortIdProperty: 'fromport' });
    // set up the model with the node and link data
    makeNodes(model);
    makeLinks(model);
    myDiagram.model = model;

    // make all but the start node invisible
    myDiagram.nodes.each((n) => {
      if (n.text !== 'Start') n.visible = false;