    extract = vtkExtractSelection()
    extract.SetInputConnection(0, elev.GetOutputPort())
    extract.SetInputConnection(1, annotationLink.GetOutputPort(2))

    def update_render_windows(obj, event):
        '''
--
            extract_selection = vtkExtractSelection()
            extract_selection.SetInputData(0, self.data)
            extract_selection.SetInputData(1, selection)
            extract_selection.Update()

            # In selection
--
    extract_selection = vtkExtractSelection()
    extract_selection.SetInputConnection(0, point_source.GetOutputPort())
    extract_selection.SetInputData(1, selection)
    extract_selection.Update()

    # In selection.
--
    extractSelection = vtkExtractSelection()
    extractSelection.SetInputConnection(0, sphereSource.GetOutputPort())
    extractSelection.SetInputData(1, selection)
    extractSelection.Update()

    # In selection
