title: how to extend service with dependencies in angular 2
body: <p>I have a parent service which has some dependencies like</p>
  
  <pre><code>@Injectable()
  export class ParentService{
    constructor(private http:Http, private customService:CustomService){}
  }
  </code></pre>
  
  <p>and I want to extend the service</p>
  
  <pre><code>@Injectable()
  export class ChildService extends ParentService{
    constructor (){
      super(??) &lt;= typescript now asking to enter two parameters according to ParentServie's constructor
    }
  }
  </code></pre>
  
  <p><strong>Edit-----------------</strong></p>
  
  <pre><code>@Injectable()
  export class ParentService{
    constructor(private http:Http, private customService:CustomService){}
    get(){this.http.get(...)}
  }
  
  @Injectable()
  export class ChildService extends ParentService{
    constructor (private http:Http, private customService:CustomService){
      super(http, customService)
    }
  }
  </code></pre>
  
  <p>Then I can use in components?</p>
  
  <pre><code>export class Cmp {
    constructor(private childService:ChildService){
      this.childService.get()
    }
  }
  </code></pre>