def test_StatLineFormatter(self):
        """
        Test that the function which formats stat lines does so appropriately.
        """
        statLine = list(pop3.formatStatResponse([]))[-1]
        self.assertEqual(statLine, b'+OK 0 0\r\n')

        statLine = list(pop3.formatStatResponse([10, 31, 0, 10101]))[-1]
        self.assertEqual(statLine, b'+OK 4 10142\r\n')

        Test that the function which formats stat lines does so appropriately.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_pop3.py