rt.data.color;
            return c ? c : 'white';
          }),
        new go.TextBlock({ margin: 3, font: 'bold 16px sans-serif', width: 140, textAlign: 'center' })
          // TextBlock.text is bound to Node.data.text
          .bind('text')
      );

    // define a Link template
    myDiagram.linkTemplate = new go.Link({
      // on mouse-over, highlight the link
      mouseDragEnter: (e, link) => (link.isHighlighted = true),
      mouseDragLeave: (e, link) => (link.isHighlighted = false),
      // o