            ids = vtkIdTypeArray()
            ids.SetNumberOfComponents(1)
            ids.InsertNextValue(picker.GetCellId())

            selection_node = vtkSelectionNode()
            selection_node.SetFieldType(vtkSelectionNode.CELL)
--
    ids = vtkIdTypeArray()
    ids.SetNumberOfComponents(1)

    # Set values.
    for i in range(10, 20):
        ids.InsertNextValue(i)
--
    ids = vtkIdTypeArray()
    ids.SetNumberOfComponents(1)

    # Specify that we want to extract cells 10 through 19
    i = 10
    while i < 20:
