    graphToPolyData = vtkGraphToPolyData()
    graphToPolyData.SetInputData(g)
    graphToPolyData.Update()

    # Create a mapper and actor
    mapper = vtkPolyDataMapper()
--
    graphToPoly = vtkGraphToPolyData()
    graphToPoly.SetInputConnection(layout.GetOutputPort())
    graphToPoly.EdgeGlyphOutputOn()

    # Set the position (0: edge start, 1: edge end) where
    # the edge arrows should go.
