'Test the exceedingly pointless LAST command, which tells you the
highest message index which you have already downloaded.'

def testLAST(self):

    p = self.pop3Server
    s = self.pop3Transport
    p.mbox.messages.append(self.extraMessage)
    p.lineReceived('LAST')
    self.assertEqual(s.getvalue(), '+OK    0\r\n')
    s.truncate(0)
