function init() {
  var $ = go.GraphObject.make;
  
  go.Shape.defineFigureGenerator('RoundedCorners', (shape, w, h) => {  // predefined in 2.0
    let param1 = shape ? shape.parameter1 : NaN;
    let param2 = shape ? shape.parameter2 : NaN;
    if (isNaN(param1) || param1 < 0) param1 = 5;  // default corner
    if (isNaN(param2) || param2 < 0) param2 = 5;  // default straight length
    param1 = Math.min(param1, w / 3);
    param1 = Math.min(param1, h / 3);

    const cpOffset = param1 * 4 * ((Math.sqrt(2) - 1) / 3);;
    const geo = new go.Geometry()
      .add(new go.PathFigure(w - param1 - param2, 0, false)
        .add(new go.PathSegment(go.PathSegment.Line, w - param1, 0))
        .add(new go.PathSegment(go.PathSegment.Bezier, w, param1, w - cpOffset, 0, w, cpOffset))
        .add(new go.PathSegment(go.PathSegment.Line, w, param1 + param2))
        .add(new go.PathSegment(go.PathSegment.Move, w, h - param1 - param2))
        .add(new go.PathSegment(go.PathSegment.Line, w, h - param1))
        .add(new go.PathSegment(go.PathSegment.Bezier, w - param1, h, w, h - cpOffset, w - cpOffset, h))
        .add(new go.PathSegment(go.PathSegment.Line, w - param1 - param2, h))
        .add(new go.PathSegment(go.PathSegment.Move, param1 + param2, h))
        .add(new go.PathSegment(go.PathSegment.Line, param1, h))
        .add(new go.PathSegment(go.PathSegment.Bezier, 0, h - param1, cpOffset, h, 0, h - cpOffset))
        .add(new go.PathSegment(go.PathSegment.Line, 0, h - param1 - param2))
        .add(new go.PathSegment(go.PathSegment.Move, 0, param1 + param2))
        .add(new go.PathSegment(go.PathSegment.Line, 0, param1))
        .add(new go.PathSegment(go.PathSegment.Bezier, param1, 0, 0, cpOffset, cpOffset, 0))
        .add(new go.PathSegment(go.PathSegment.Line, param1 + param2, 0)));
    return geo;
  });

  myDiagram =
    $(go.Diagram, "myDiagramDiv",
      {
        initialContentAlignment: go.Spot.Center,
        "undoManager.isEnabled": true
      }
    );
  
  var cornerAdornment =
    $(go.Adornment, "Auto",
      $(go.Shape, "RoundedCorners", { strokeWidth: 2, stroke: "darkgray", strokeCap: "round", fill: null /*, parameter2: 10 */ }),
      $(go.Placeholder, { margin: 3 })
    );

  // define a simple Node template
  myDiagram.nodeTemplate =
    $(go.Node, "Auto",  // the Shape will go around the TextBlock
      {
        selectionAdorned: false,
        selectionChanged: (p) => {
          if (p.isSelected) {
            cornerAdornment.adornedObject = p;
            p.addAdornment("Highlight", cornerAdornment);
          } else {
           p.removeAdornment("Highlight"); 
          }
        }
      },
      $(go.Shape, "RoundedRectangle", { strokeWidth: 0 },
        // Shape.fill is bound to Node.data.color
        new go.Binding("fill", "color")),
      $(go.TextBlock,
        { margin: 8 },  // some room around the text
        // TextBlock.text is bound to Node.data.key
        new go.Binding("text", "key"))
    );
  


  // but use the default Link template, by not setting Diagram.linkTemplate

  // create the model data that will be represented by Nodes and Links
  myDiagram.model = new go.GraphLinksModel(
  [
    { key: "Alpha", color: "lightblue" },
    { key: "Beta", color: "orange" },
    { key: "Gamma", color: "lightgreen" },
    { key: "Delta", color: "pink" }
  ],
  [
    { from: "Alpha", to: "Beta" },
    { from: "Alpha", to: "Gamma" },
    { from: "Beta", to: "Beta" },
    { from: "Gamma", to: "Delta" },
    { from: "Delta", to: "Alpha" }
  ]);
}