r2a = pg.PolyLineROI([[0,0], [10,10], [10,30], [30,10]], closed=True)
pts = np.array([[0,0], [10,10], [10,30], [30,10]])
center = pts.mean(0)
min = np.min(pts, axis=0)
max = np.max(pts, axis=0)
r2a.addScaleHandle(min, center)
r2a.addScaleHandle(max, center)
v2a.addItem(r2a)