def test_negativeTTL(self):
        """
        Attempting to create a L{dns.RRHeader} instance with a negative TTL
        causes L{ValueError} to be raised.
        """
        self.assertRaises(
            ValueError, dns.RRHeader, "example.com", dns.A,
            dns.IN, -1, dns.Record_A("127.0.0.1"))

        Attempting to create a L{dns.RRHeader} instance with a negative TTL
        causes L{ValueError} to be raised.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_dns.py