def test_intersection(self):
r1 = Rect(Point(10, 10), Size(30, 30))
r2 = Rect(Point(20, 20), Size(10, 10))
r = r1.intersection(r2)
self.assertEqual(r, r2)
r3 = Rect(Point(10, 10), Size(20, 40))
r4 = Rect(Point(15, 15), Size(15, 15))
r = r3.intersection(r4)
self.assertEqual(r, Rect(Point(15, 15), Size(15, 15)))
r5 = Rect(Point(4, 4), Size(8, 8))
r6 = Rect(Point(9, 9), Size(12, 12))
r = r5.intersection(r6)
self.assertEqual(r, Rect(Point(9, 9), Size(3, 3)))
r7 = Rect(Point(5, 5), Size(5, 5))
r8 = Rect(Point(5, 10), Size(10, 10))
r = r7.intersection(r8)
self.assertEqual(r, Rect(Point(5, 10), Size(5, 0)))
