def METHOD_NAME(self, mocked_deselect):
    plot_data = ArrayPlotData()
    arr = np.arange(4.0)
    plot_data.set_data("x", arr)
    plot_data.set_data("y", arr)
    plot = Plot(plot_data)
    renderer = plot.plot(("x", "y"))[0]
    tool = RangeSelection(renderer)
    renderer.tools.append(tool)
    new_renderer = plot.plot(("x", "y"), type='scatter')[0]
    tool.plot = new_renderer
    # attempt to trigger change handler for the index_mapper trait on the
    # RangeSelection tool's plot
    # assign a new mapper with same attrs
    new_renderer.index_mapper = LinearMapper(
        range=new_renderer.index_mapper.range,
        stretch_data=new_renderer.index_mapper.stretch_data
    )
    mocked_deselect.assert_called_once()