def METHOD_NAME():
    bool_df = pd.DataFrame(
        [
            {"bool_col": True, "int_col": 0, "float_col": 3.0},
            {"bool_col": False, "int_col": 100, "float_col": 0.7},
        ]
    )
    copy_of_df = bool_df.copy()
    widget = AutoVizWidget(
        df,
        encoding,
        renderer,
        ipywidget_factory,
        encoding_widget,
        ipython_display,
        spark_events=spark_events,
        testing=True,
    )
    result = AutoVizWidget._convert_to_displayable_dataframe(bool_df)
    # Ensure original DF not changed
    assert_frame_equal(bool_df, copy_of_df)
    assert_series_equal(bool_df["int_col"], result["int_col"])
    assert_series_equal(bool_df["float_col"], result["float_col"])
    assert result.dtypes["bool_col"] == object
    assert len(result["bool_col"]) == 2
    assert result["bool_col"][0] == "True"
    assert result["bool_col"][1] == "False"
    spark_events.emit_graph_render_event.assert_called_once_with(encoding.chart_type)