    diskSource = vtkDiskSource()

    # Create a mapper and actor.
    mapper = vtkPolyDataMapper()
    mapper.SetInputConnection(diskSource.GetOutputPort())

--
    diskSource = vtkDiskSource()
    diskSource.Update()

    featureEdges = vtkFeatureEdges()
    featureEdges.SetInputConnection(diskSource.GetOutputPort())
    featureEdges.BoundaryEdgesOn()
