def METHOD_NAME(self):
    """
    Returns a dictionary with the bounding box data.
    EXAMPLES::
        sage: b = bar_chart([-2.3,5,-6,12])
        sage: d = b.get_minmax_data()
        sage: d['xmin']
        0
        sage: d['xmax']
        4
    """
    return minmax_data([0, len(self.datalist)], self.datalist, dict=True)