def test_fetchUIDNonIntegerFound(self):
        """
        If the server responds with a non-integer where a message sequence
        number is expected, the L{Deferred} returned by L{IMAP4Client.fetchUID}
        fails with L{IllegalServerResponse}.
        """
        d = self.client.fetchUID('1')
        self.assertEqual(self.transport.value(), b'0001 FETCH 1 (UID)\r\n')
        self.client.lineReceived(b'* foo FETCH (UID 22)')
        self.client.lineReceived(b'0001 OK FETCH completed')
        self.failureResultOf(d, imap4.IllegalServerResponse)

        If the server responds with a non-integer where a message sequence
        number is expected, the L{Deferred} returned by L{IMAP4Client.fetchUID}
        fails with L{IllegalServerResponse}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py