def METHOD_NAME(self, single_plot_page: SinglePlotPage) -> None:
    plot = _make_plot()
    page = single_plot_page(plot)
    # ensure clicking adds a point
    page.drag_canvas_at_position(plot, 200, 200, 50, 50)
    page.eval_custom_action()
    expected = {'xs': [[1.6216216216216217, 2.027027027027027, 2.027027027027027, 2.027027027027027]],
                'ys': [[1.5, 1.125, 1.125, 1.125]]}
    assert cds_data_almost_equal(page.results, expected)
    assert page.has_no_console_errors()