error ' Property map does not exist on type Observable

Question

Below is my service.ts. I have added map and catch separately. Still getting property does not exist with observable<response>

import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Observable'; // for handling service     response - like promise

import { DashboardModel } from '../model/dashboard.model' 



import 'rxjs/add/operator/map';   
import 'rxjs/add/operator/catch';// Import RxJs required methods

@Injectable()

export class AppService {
constructor(private http: Http) { }
// private instance variable to hold base url
private baseUrl = 'https://www.google.co.in';


// Fetch all existing comments
getDetails(): Observable<DashboardModel[]> {

    // ...using get request
    return this.http.get(this.baseUrl)
        // ...and calling .json() on the response to return data
        .map((res: Response) => res.json())
        //...errors if any
        .catch((error: any) => Observable.throw(error.json().error || 'Server error'));
}
} 

edit : i have seen solutions where to add map, catch etc to be imported separately. Even then, i am getting same error.