e.part.findObject('SHAPE');
      var c = shape.actualBounds.center;
      return c.directionPoint(p);
    }

    myDiagram.model = new go.GraphLinksModel(
      [
        { key: 1, text: 'Alpha', value: 35 },
        { key: 2, text: 'Beta', color: 'green', max: 140, value: 70 }
      ],
      [{ from: 1, to: 2 }]
    );

    loop();
  }

  // change each gauge's value several times a second
  function loop() {
    setTimeout(() => {
      myDiagram.startTransaction();
      myDiagram.nodes.each((node) => {