                      -sweep,
                                0,
                                0,
                                radius - layerThickness,
                                radius - layerThickness
                              ).close()
                            )
                        );
                    }),
                  new go.Shape('Circle', { width: 2, height: 2, fill: '#444' })
                )
            ),
          new go.TextBlock({ row: 1, font: 'bold 11pt sans-serif'