'If an intermediate response includes no glue records for the
authorities, separate queries are made to find those addresses.'

def test_missingGlue(self):

    servers = {('1.1.2.3', 53): {('foo.example.com', A): {'authority': [('foo.example.com', Record_NS('ns1.example.org'))]}, ('ns1.example.org', A): {'answers': [('ns1.example.org', Record_A('10.0.0.1'))]}}, ('10.0.0.1', 53): {('foo.example.com', A): {'answers': [('foo.example.com', Record_A('10.0.0.2'))]}}}
    resolver = self._getResolver(servers)
    d = resolver.lookupAddress('foo.example.com')
    d.addCallback(getOneAddress)
    d.addCallback(self.assertEqual, '10.0.0.2')
    return d
