def test_arg_literalUnmatchedBraces(self):
        """
        A literal with unmatched braces raises
        L{IllegalClientResponse}.
        """
        self.assertRaises(imap4.IllegalClientResponse,
                          self.server.arg_literal, b"{10")
        self.assertRaises(imap4.IllegalClientResponse,
                          self.server.arg_literal, b"10}")

        A literal with unmatched braces raises
        L{IllegalClientResponse}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py