'If there is an error resolving the nameserver in a delegation response,
the L{Deferred} returned by L{Resolver.lookupAddress} fires with that
error.'

def test_delegationLookupError(self):

    servers = {('1.1.2.3', 53): {('example.com', A): {'authority': [('example.com', Record_NS('ns1.example.com'))]}, ('ns1.example.com', A): {'rCode': ENAME}}}
    resolver = self._getResolver(servers)
    d = resolver.lookupAddress('example.com')
    return self.assertFailure(d, DNSNameError)
