Block({ margin: 8 }).bind('text')
      ).bindTwoWay('scale');

    // 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({
      nodeDataArray: [
        { key: 1, text: 'Alpha', color: 'lightblue' },
        { key: 2, text: 'Beta', color: 'orange' },
        { key: 3, text: 'Gamma', color: 'lightgreen' },
        { key: 4, text: 'Delta', color: 'pink' }
      ],
      