'Return a :class:`Bbox` that contains all of the given bboxes.'

@staticmethod
def union(bboxes):

    if (not len(bboxes)):
        raise ValueError(u"'bboxes'    cannot    be    empty")
    x0 = np.min([bbox.xmin for bbox in bboxes])
    x1 = np.max([bbox.xmax for bbox in bboxes])
    y0 = np.min([bbox.ymin for bbox in bboxes])
    y1 = np.max([bbox.ymax for bbox in bboxes])
    return Bbox([[x0, y0], [x1, y1]])
