def bbox(self):
bbs = [seg.bbox() for seg in self._segments]<EOL>xmins, xmaxs, ymins, ymaxs = list(zip(*bbs))<EOL>xmin = min(xmins)<EOL>xmax = max(xmaxs)<EOL>ymin = min(ymins)<EOL>ymax = max(ymaxs)<EOL>return xmin, xmax, ymin, ymax<EOL>
returns a bounding box for the input Path object in the form
        (xmin, xmax, ymin, ymax).