How to use the pycares.ARES_NI_LOOKUPSERVICE function in pycares

def test_getnameinfo(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel.getnameinfo(('127.0.0.1', 80), pycares.ARES_NI_LOOKUPHOST|pycares.ARES_NI_LOOKUPSERVICE, cb)
        self.wait()
        self.assertNoError(self.errorno)
        self.assertEqual(type(self.result), pycares.ares_nameinfo_result)
        self.assertIn(self.result.node, ('localhost.localdomain', 'localhost'))
        self.assertEqual(self.result.service, 'http')

def getnameinfo(self, sockaddr, flags):
        if not isinstance(flags, int):
            raise TypeError('an integer is required')
        if not isinstance(sockaddr, tuple):
            raise TypeError('getnameinfo() argument 1 must be a tuple')
        try:
            port = int(sockaddr[1])
        except Exception:
            raise TypeError('an integer is required')
        _flags = pycares.ARES_NI_LOOKUPHOST|pycares.ARES_NI_LOOKUPSERVICE
        for socket_flag, ares_flag in self._ares_flag_map:
            if socket_flag & flags:
                _flags |= ares_flag
        try:
            result = self.getaddrinfo(sockaddr[0], sockaddr[1], family=socket.AF_UNSPEC, socktype=socket.SOCK_DGRAM)
        except ValueError:
            raise socket.gaierror(8, 'nodename nor servname provided, or not known')
        if len(result) != 1:
            raise socket.error('sockaddr resolved to multiple addresses')
        family, socktype, proto, name, address = result[0]
        if family == socket.AF_INET:
            if len(sockaddr) != 2:
                raise socket.error("IPv4 sockaddr must be 2 tuple")
        elif family == socket.AF_INET6:
            address = address[:2] # TODO: is this ok?
        waiter = Waiter(self.hub)