category: 'Switch' }
      ])
    });

    // initialize Overview
    myOverview = new go.Overview('myOverviewDiv', {
      observed: myDiagram,
      contentAlignment: go.Spot.Center
    });

    load();
  }

  // Show the diagram's model in JSON format
  function save() {
    document.getElementById('mySavedModel').value = myDiagram.model.toJson();
    myDiagram.isModified = false;
  }
  function load() {
    myDiagram.model = go.Model.fromJson(document.getElementById('mySavedModel').value);
  }

  functi