我的离子代码或使用jsforce有什么问题？

Question

我只是尝试在我的ionic2应用程序中订阅salesforce中的主题，它甚至允许rest api调用但在订阅主题时出错：

 Error during WebSocket handshake: Unexpected response code: 405

这是完整的代码：

import { Component } from '@angular/core';

import { NavController } from 'ionic-angular';

import * as jsforce from "jsforce";

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController) {



      var conn = new jsforce.Connection({

         loginUrl : 'https://login.salesforce.com'
      });

      var username = 'XXXXXXXXXXXXXXX';
      var password = 'XXXXXXXXXXXXXXX';

      conn.login(username, password, function(err, userInfo) {
        if (err) { return console.error(err); }

            console.log(conn.accessToken);
            console.log(conn.instanceUrl);

           //this part of code works
            conn.query("SELECT Id, Name FROM Account", function(err, result) {
              if (err) { return console.error(err); }
              console.log("total : " + result.totalSize);
              console.log("fetched : " + result.records.length);
            });

           // this part of codes doesn't work
            conn.streaming.topic("InvoiceStatementUpdates").subscribe(function(message) {
              console.log('Event Type : ' + message.event.type);
              console.log('Event Created : ' + message.event.createdDate);
              console.log('Object Id : ' + message.sobject.Id);
            });

            // logged in user property
            console.log("User ID: " + userInfo.id);
            console.log("Org ID: " + userInfo.organizationId);

      });




  }

}