请任何人都可以帮助ews-javascript-api中的GetUserAvailability方法。我目前正在使用这个exchange api开发一个房间预订系统，但是我遇到了一个问题，我找不到解决方案。请需要你的帮助伙计们

const room = 'roomemail@email.com' 
const user = 'email@email.com' 
var myPwd = 'password'

// Dependencies
var ews = require("ews-javascript-api");

// Debug Mode
ews.EwsLogging.DebugLogEnabled = false;

// Login to Exchange URI, Username and Password, Version of Exchange
var exch = new ews.ExchangeService(ews.ExchangeVersion.Exchange2013);
exch.Credentials = new ews.ExchangeCredentials(user, myPwd);  
exch.Url = new ews.Uri("https://mail.domain.com");

// Check Availability
var now = new Date();
now.setMinutes(now.getMinutes() + 1);

var startTime = new ews.DateTime(now);
var tw = new ews.TimeWindow(ews.DateTime.Now, ews.DateTime.Now.AddHours(8));
var attendee = new ews.AttendeeInfo("roomemail@email.com");
var result = new exch.GetUserAvailability(attendee, tw, ews.AvailabilityData.FreeBusyAndSuggestions);

console.log(result);

然后我得到了这个错误:

../ews javascript api/js/Core/EwsUtility.js:567抛出新的ArgumentException_1.ArgumentException（Strings_1.Strings.CollectionIsEmpty，paramName）；^异常：集合为空。at Function.EwsUtilities.ValidateParamCollection（/Users/rsatraj/node_moduless/ews-javascript api/js/Core/EwsUtility.js:567:19）at new ExchangeService.GetUserAvailability（/Users/rsatraj/node_modules/ews javascript api/js/Core/ExchangeService.js:1402:37）at Object。（/Users/rsatraj/booking.js:46:14）在模块_在Function.module.runMain（module.js:69:3:10）的Function.Modules_load（module.js:693:10）处（bootstrap_node.js:191:16），在启动时（bootstrap.node.js:191:16）

截至目前，我不确定该怎么办。你们能帮我这个吗？任何信息都会有所帮助！真的很感激