How to use the xhr2.prototype function in xhr2

import { ngExpressEngine } from '@nguniversal/express-engine'
import { AppServerModule } from './angular/server.angular.module'
import { argv } from 'yargs'
import { resolve } from 'path'
import { rollbarInit } from './add-ons/rollbar'
import { useApi } from './rest-api/index'
import ms = require('ms')

const shrinkRay = require('shrink-rayed')
const minifyHTML = require('express-minify-html')
const bunyanMiddleware = require('bunyan-middleware')
const xhr2 = require('xhr2')
const cors = require('cors')

// tslint:disable-next-line:no-object-mutation
xhr2.prototype._restrictedHeaders.cookie = false

require('ts-node/register')

const app = express()
rollbarInit(app)
const isProd = argv['build-type'] === 'prod' || argv['prod']
const isEndToEndTest = argv.e2e

const staticOptions = {
  index: false,
  maxAge: isProd ? ms('1y') : ms('0'),
  setHeaders: (res: express.Response, path: any) => {
    res.setHeader(
      'Expires',
      isProd
        ? new Date(Date.now() + ms('1y')).toUTCString()

import 'zone.js/dist/zone-node';
import 'reflect-metadata';
import { renderModule, renderModuleFactory } from '@angular/platform-server';
import { APP_BASE_HREF } from '@angular/common';
import { enableProdMode } from '@angular/core';
import { provideModuleMap } from '@nguniversal/module-map-ngfactory-loader';
import { createServerRenderer } from 'aspnet-prerendering';
export { AppServerModule } from './app/app.server.module';
import { COOKIES } from '@app/models';

// This allows to set cookies on server
// Only cookie used in this app is culture cookie
import * as xhr2 from 'xhr2';
xhr2.prototype._restrictedHeaders = {};

enableProdMode();

export default createServerRenderer(params => {
    const { AppServerModule, AppServerModuleNgFactory, LAZY_MODULE_MAP } = (module as any).exports;
    const options = {
        document: params.data.originalHtml,
        url: params.url,
        extraProviders: [
            provideModuleMap(LAZY_MODULE_MAP),
            { provide: APP_BASE_HREF, useValue: params.baseUrl },
            { provide: 'BASE_URL', useValue: params.origin + params.baseUrl },
            { provide: COOKIES, useValue: params.data.cookies }
        ]
    };

import { sitemap } from './server.sitemap'
import { exists, existsSync } from 'fs'
import { argv } from 'yargs'
import { useApi } from './api'
import { join, resolve } from 'path'
import { useWebSockets } from './server.web-socket'
import { ANGULAR_APP_CONFIG, FB_SERVICE_ACCOUNT_CONFIG } from './server.config'
import http = require('http')
import ms = require('ms')

const shrinkRay = require('shrink-ray')
const minifyHTML = require('express-minify-html')
const bunyanMiddleware = require('bunyan-middleware')
const xhr2 = require('xhr2')

xhr2.prototype._restrictedHeaders.cookie = false

require('ts-node/register')

const app = express()
const server = http.createServer(app)
const root = './dist'
const port = process.env.PORT || argv['port'] || 8001
const host = process.env.HOST || argv['host'] || 'http://localhost'
const isProd = argv['build-type'] === 'prod' || argv['prod']
const isTest = argv['e2e']

const staticOptions = {
  index: false,
  maxAge: isProd ? ms('1yr') : ms('0'),
  setHeaders: (res: express.Response, path: any) => {
    res.setHeader('Expires', isProd

XMLHttpRequest.prototype.open = function(method, url, async, user, password) {
  if (!url.match(/^https?:\/\//))
    url = resolve(this.location.href, url);
  return BaseXMLHttpRequest.prototype.open.call(
      this, method, url, async, user, password);
}