升级到angular 8后，找不到'@angularcommonhttpsrcclient'的HttpObserve。

Question

import { HttpObserve } from '@angular/common/http/src/client';
import { HttpParams, HttpHeaders } from '@angular/common/http';

type responseType = 'arraybuffer' | 'blob' | 'json' | 'text';

export interface RequestOptions {
  body?: any;
  headers?: HttpHeaders;
  params?: HttpParams;
  observe?: HttpObserve;
  reportProgress?: boolean;
  responseType?: responseType;
  withCredentials?: boolean;
}

升级到angular 8后，上面的代码出现了下面提到的错误，有什么帮助吗？

error TS2307: Cannot find module '@angular/common/http/src/client'.