ed': false
    });

    // This model includes all of the data
    myWholeModel = new go.TreeModel(); // must match the model used by the Diagram, below

    // The virtualized layout works on the full model, not on the Diagram Nodes and Links
    myDiagram.layout.model = myWholeModel;

    // Do not set myDiagram.model = myWholeModel -- that would create a zillion Nodes and Links!
    // In the future Diagram may have built-in support for virtualization.
    // For now, we have to implement virtualization 