这是从Angular 2到Angular 4的已知突破性变化吗？

Question

我已经尽力检查这是否是一个已知的突破性变化，但我看不到任何直接解决它的问题。

在Angular 2（最高2.4.9）中，我可以这样做：

import { Injectable } from '@angular/core';
import { Headers, RequestOptions, Http, URLSearchParams, ResponseContentType } from '@angular/http';

import 'rxjs/add/operator/toPromise';

import * as debugModule from 'debug';

@Injectable()
export class SomeService {
    private someUrl = 'http://127.0.0.1:4000/api/stuff';
    protected debug = debugModule('some-service');
    protected defaultHeaders = new Headers({'Content-Type': 'application/json'});
    protected defaultParams = new URLSearchParams();
    protected defaultOptions = new RequestOptions({headers: this.defaultHeaders, search: this.defaultParams});

  constructor (){
    this.debug("Are these the same?");
    this.debug(this.defaultOptions.search == this.defaultParams);
  }

}

......它会输出：

some-service: Are these the same?
some-service: true

如果我没有把所有内容升级到Angular 4.0.1我现在得到这个：

some-service: Are these the same?
some-service: false

为什么这些不再是同一个对象？ 这打破了我的应用程序，因为我在某些情况下使用defaultParams来传递和扩充搜索参数（比如添加用户的id）。 我想我可以解决这个问题，但是传递defaultOptions并对其进行操作，但它会在很多地方改变我的应用程序。

在我从Angular 2升级到Angular 4的过程中，我没有看到任何可以解决这个问题的内容。

是什么改变使得RequestOptions创建了一个你传递它的副本而不是一个引用（或者这里发生了什么）的副本？

根据要求，我的package.json文件。 是的我在依赖项部分中有typescript而不是devDependencies - 目前有一个原因与此问题无关：

{
  "name": "my-name",
  "version": "0.0.1",
  "scripts": {
    "start": "npm run clean && tsc && npm run moveassets && NODE_ENV=production ./moveConfig && NODE_ENV=production forever start -a -l front.log -e front-err.log server.js",
    "startdev": "npm run clean && tsc && npm run moveassets && concurrently \"npm run tsc:w\" \"npm run lite\" \"npm run watchassets\"  ",
    "lite": "lite-server",
    "postinstall-old": "typings install",
    "postinstall": "npm run moveassets && chmod +x moveConfig",
    "tsc": "tsc",
    "tsc:w": "tsc -w",
    "clean": "rm -rf build/*",
    "typings": "typings",
    "moveassets": "rsync -a --include='*.css' --include='*.html' --include='*.png' --include='*/' --exclude='*' ./app/ ./build/",
    "watchassets": "onchange 'app/**/*.css' 'app/**/*.html' -e 'build/*'  -v -- npm run moveassets",
    "watch-css": "node-sass -w app/**/*.scss -o app/**/"
  },
  "license": "UNLICENSED",
  "dependencies": {
    "@angular/common": "^4.0.1",
    "@angular/compiler": "^4.0.1",
    "@angular/compiler-cli": "^4.0.1",
    "@angular/core": "^4.0.1",
    "@angular/forms": "^4.0.1",
    "@angular/http": "^4.0.1",
    "@angular/material": "^2.0.0-beta.2",
    "@angular/platform-browser": "^4.0.1",
    "@angular/platform-browser-dynamic": "^4.0.1",
    "@angular/platform-server": "^4.0.1",
    "@angular/router": "^4.0.1",
    "@angular/upgrade": "^4.0.1",
    "@types/async": "^2.0.38",
    "@types/core-js": "^0.9.39",
    "@types/debug": "0.0.29",
    "@types/express": "4.0.35",
    "@types/jasmine": "2.5.41",
    "@types/node": "0.0.2",
    "angular2-chartjs": "^0.1.6",
    "angulartics2": "1.6.3",
    "bootstrap": "3.3.7",
    "core-js": "2.4.1",
    "debug": "2.6.0",
    "express": "4.14.0",
    "forever": "^0.15.3",
    "moment": "2.17.1",
    "ng2-auto-complete": "^0.10.10",
    "ng2-google-place-autocomplete": "^1.4.2",
    "ng2-pdf-viewer": "1.0.2",
    "primeng": "1.1.4",
    "randomcolor": "0.4.4",
    "reflect-metadata": "0.1.9",
    "rxjs": "5.0.3",
    "systemjs": "0.19.42",
    "typescript": "^2.2.1",
    "zone.js": "0.7.6"
  },
  "devDependencies": {
    "concurrently": "2.2.0",
    "lite-server": "2.2.2",
    "node-sass": "3.13.1",
    "onchange": "3.2.1",
  }
}