def test_LAST(self):
        """
        Test the exceedingly pointless LAST command, which tells you the
        highest message index which you have already downloaded.
        """
        p = self.pop3Server
        s = self.pop3Transport
        p.mbox.messages.append(self.extraMessage)

        p.lineReceived(b'LAST')
        self.assertEqual(
            s.getvalue(),
            b"+OK 0\r\n")
        s.seek(0)
        s.truncate(0)

        Test the exceedingly pointless LAST command, which tells you the
        highest message index which you have already downloaded.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_pop3.py