     myDiagram.layout.invalidateLayout();
              myDiagram.commitTransaction('toggle assistant');
            }
          }
        })
          .add(new go.TextBlock('Toggle Assistant'))
      );

    // define the Link template
    myDiagram.linkTemplate = new go.Link({ routing: go.Routing.Orthogonal, corner: 5 })
      .add(new go.Shape({ strokeWidth: 4, stroke: '#00a4a4' })); // the link shape

    // read in the JSON-format data from the "mySavedModel" element
    load();

    // support editing