title: Property 'map' does not exist on type 'Subscription'
body: <p>
  I am trying to fire the error callback in <code>http-service</code> file and if any error exists I am calling the data from local service. I am returning this to a service file called <code>app-config-service</code>.</p>
  
  <p>Code for <code>http-service.ts</code>:</p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import {Http} from '@angular/http';
  import 'rxjs/add/operator/map';
  import { MockService } from './mock-service';
  
  @Injectable()
  export class HttpRestService {
  
      constructor(private http:Http,mockService:MockService ) {
  
      }
  
      get(pUrl) {
          return this.http.get(pUrl).subscribe(
               function(response) { res =&gt; response.json()},
               function(error) { res =&gt; this.mockService.userMethods(pUrl) },
               function() { console.log("the subscription is completed")}
          );
      }
  
      post(pUrl, pData) {
          return this.http.post(pUrl, pData).map(res =&gt; res.json());
      }
  }
  </code></pre>
  
  <p>Code for <code>app-config-service.ts</code>:</p>
  
  <pre><code>import { Injectable } from '@angular/core';
  import 'rxjs/add/operator/map';
  import { HttpRestService } from './http-service';
  @Injectable()
  export class AppConfigService {
      constructor(private httpRestService: HttpRestService) {
      }
      testAPIMethod(pUrl) {
          return this.httpRestService.get(pUrl).map(res =&gt; res);
      }
  }
  </code></pre>
  
  
  
  <p>As per my knowledge subscribe is used to manipulate the result received, and map is used to copy the data directly without any change.</p>
  
  <p>So I have used subscribe and map in those situations. </p>
  
  <p>I don't know why an error is being triggered as I am a newbie to typescript. </p>
  
  <p>The error is as follows:</p>
  
  <pre><code>typescript: E:/ActiveProjects/IonBase/src/services/app-config-service.ts, line: 14
          Property 'map' does not exist on type 'Subscription'.
  
    L13:  testAPIMethod(pUrl) {
    L14:      return this.httpRestService.get(pUrl).map(res =&gt; res);
  </code></pre>
  
  
  
  <p>What can I do to fix this?</p>