How to use the zeroconf.ServiceStateChange function in zeroconf

def _onServiceChanged(self, zero_conf, service_type, name, state_change):
        if state_change == ServiceStateChange.Added:
            Logger.log("d", "Bonjour service added: %s" % name)

            # First try getting info from zero-conf cache
            info = ServiceInfo(service_type, name, properties={})
            for record in zero_conf.cache.entries_with_name(name.lower()):
                info.update_record(zero_conf, time(), record)

            for record in zero_conf.cache.entries_with_name(info.server):
                info.update_record(zero_conf, time(), record)
                if info.address:
                    break

            # Request more data if info is not complete
            if not info.address:
                Logger.log("d", "Trying to get address of %s", name)
                info = zero_conf.get_service_info(service_type, name)