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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_bbox(self, points=None):
 """ Get bounding box of this object. Returns ------- (p1, p2, p3, p4):
 a 4-tuple of the points in data coordinates, beginning with the lower-left and proceeding counter-clockwise. """

        if points is None:
            x1, y1, x2, y2 = self.get_llur()
            return ((x1, y1), (x1, y2), (x2, y2), (x2, y1))
        else:
            return trcalc.strip_z(trcalc.get_bounds(points))