How to use the supervisor.http.NOT_DONE_YET function in supervisor

except RPCError, e:
                results.append(
                    {'name':process.config.name,
                     'group':group.config.name,
                     'status':e.code,
                     'description':e.text})
            else:
                results.append(
                    {'name':process.config.name,
                     'group':group.config.name,
                     'status':Faults.SUCCESS,
                     'description':'OK'}
                    )

            if callbacks:
                return NOT_DONE_YET

            return results

def handleAction(self):
        form = self.context.form
        action = form.get('action')
        if action:
            # trigger deferred action and wait
            processname = form.get('processname')
            if not self.callback:
                self.callback = self.make_callback(processname, action)
                return NOT_DONE_YET
            # intermediate check
            message = self.callback()
            if message is NOT_DONE_YET: return NOT_DONE_YET
            # post to write message
            if message is not None:
                location = form['SERVER_URL'] + form['PATH_TRANSLATED'] + '?appli={}&message={}&gravity={}'.format(self.applicationName, urllib.quote(message[1]), message[0])
                self.context.response['headers']['Location'] = location

def more(self):
        if self.finished:
            return ''
        try:
            response = self.callback()
            if response is NOT_DONE_YET:
                return NOT_DONE_YET

            self.finished = True
            return self.sendresponse(response)

        except:
            tb = traceback.format_exc()
            # this should go to the main supervisor log file
            self.request.channel.server.logger.log('Web interface error', tb)
            self.finished = True
            self.request.error(500)

def more (self):
        while len(self.producers):
            p = self.producers[0]
            d = p.more()
            if d is NOT_DONE_YET:
                return NOT_DONE_YET
            if d:
                return d
            else:
                self.producers.pop(0)
        else:
            return b''

def __call__(self):
        body = self.render()
        if body is NOT_DONE_YET:
            return NOT_DONE_YET

        response = self.context.response
        headers = response['headers']
        headers['Content-Type'] = self.content_type
        headers['Pragma'] = 'no-cache'
        headers['Cache-Control'] = 'no-cache'
        headers['Expires'] = http_date.build_http_date(0)
        response['body'] = body
        return response

if isinstance(value, types.FunctionType):
                    callbacks.append(value)
                else:
                    results.append(value)

            # we are done when there's no callback and no more calls queued
            if callbacks or remaining_calls:
                return NOT_DONE_YET
            else:
                return results
        multi.delay = 0.05

        # optimization: multi() is called here instead of just returning
        # multi in case all calls complete and we can return with no delay.
        value = multi()
        if value is NOT_DONE_YET:
            return multi
        else:
            return value

        @functools.wraps(meth)
        def wrapper(*args, **kwargs):
            args[0]._log.debug('0RPC: called {}'.format(meth.__name__))
            result = meth(*args, **kwargs)
            if callable(result):
                r = NOT_DONE_YET
                while r is NOT_DONE_YET:
                    sleep(0.1)
                    r = result()
                result = r
            return result
        return wrapper

def stopall():
                    if callback() is NOT_DONE_YET:
                        return NOT_DONE_YET
                    else:
                        return 'All stopped at %s' % time.ctime()
                stopall.delay = 0.05

def more (self):
        if self.producer:
            result = self.producer.more()
            if result is NOT_DONE_YET:
                return NOT_DONE_YET
            if not result:
                self.producer = None
                self.function (self.bytes)
            else:
                self.bytes += len(result)
            return result
        else:
            return b''

def render(self):
        form = self.context.form
        response = self.context.response
        processname = form.get('processname')
        action = form.get('action')
        message = form.get('message')

        if action:
            if not self.callback:
                self.callback = self.make_callback(processname, action)
                return NOT_DONE_YET

            else:
                message =  self.callback()
                if message is NOT_DONE_YET:
                    return NOT_DONE_YET
                if message is not None:
                    server_url = form['SERVER_URL']
                    location = server_url + '?message=%s' % urllib.quote(
                        message)
                    response['headers']['Location'] = location

        supervisord = self.context.supervisord
        rpcinterface = RootRPCInterface(
            [('supervisor',
              SupervisorNamespaceRPCInterface(supervisord))]
            )