lang-js" id="defaultPort"><code>
  diagram.nodeTemplate =
    new go.Node("Vertical",
      { fromSpot: go.Spot.Right, toSpot: go.Spot.Left })   // port properties on the node
      .add(
        new go.Shape("Ellipse",
          { width: 30, height: 30, fill: "green" }),
        new go.TextBlock({ font: "20px sans-serif" })
          .bind("text")
      );

  const nodeDataArray = [
    { key: 1, text: "Alpha" },
    { key: 2, text: "Beta" }
  ];
  const linkDataArray = [
    { from: 1, to: 2 }
  ];
  diag