def test_fetchParserQuotedHeader(self):
        """
        Parsing a C{BODY} whose C{HEADER} values require quoting
        results in a object that perserves that quoting when
        serialized.
        """
        p = imap4._FetchParser()
        p.parseString(b'BODY[HEADER.FIELDS ((Quoted)]')
        self.assertEqual(len(p.result), 1)
        self.assertEqual(p.result[0].peek, False)
        self.assertIsInstance(p.result[0], p.Body)
        self.assertIsInstance(p.result[0].header, p.Header)
        self.assertEqual(bytes(p.result[0]),
                         b'BODY[HEADER.FIELDS ("(Quoted")]')

        Parsing a C{BODY} whose C{HEADER} values require quoting
        results in a object that perserves that quoting when
        serialized.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py