def test_getLast(self):
        """
        Accessing L{MessageSet.last} returns the last value.
        """
        m = MessageSet(1, None)
        m.last = 2
        self.assertEqual(m.last, 2)

        Accessing L{MessageSet.last} returns the last value.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py