def testintersection_update(self):
c = Bitset(self.b2)
c.intersection_update(self.b1)
self.assertEqual(c, self.b2.intersection(self.b1))
c = Bitset(self.b1)
c.intersection_update(self.b2)
self.assertEqual(c, self.b1.intersection(self.b2))
c = Bitset(self.b1)
c.intersection_update(self.b4)
self.assertEqual(c, self.b1.intersection(self.b4))
