code: def get_bbox(self, points=None):
          
          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))
docs: 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.