测试具有http依赖性的构造函数的angular2服务

如何为具有依赖于http的构造函数的以下类编写jasmine测试用例

import {Injectable} from 'angular2/core';
import {Http, HTTP_PROVIDERS} from 'angular2/http';

@Injectable()
export class MockUserService {
    items:Array;

    constructor(http:Http){
        http.get('http://127.0.0.1:8080/src/data/names.json')
        .subscribe(res => {
            this.items = res;
            console.log('results found');
        })
    }
}

 it('Testing user login', inject([MockUserService,Http], (mockUserService:MockUserService ) => {
   let http:Http;
        let mockUserService: MockUserService = new MockUserService(http);
     expect(1+1).toEqual(2);

  });
  );