title: Angular Service response remembers initial parameter
body: <p>Below a simplified version of my call to my Service.</p>
  <p>Component:</p>
  <pre><code>for (let platform of this.platforms) {
  
      this.artistsService.getFollowers(uuid, platform)
     .subscribe((data: any[]) =&gt; { console.log(platform); })
  }
  </code></pre>
  <p>Service:</p>
  <pre><code>  getFollowers(uuid: string, platform: string): Observable&lt;any[]&gt; {
      return this.http.get&lt;any[]&gt;(this.baseUrl + '/followers/' + platform + '/' + uuid + '?format=json', httpOptions)
        .pipe(
          catchError(this.handleError('getFollowers', []))
        );
    }
  </code></pre>
  <p>I would like the callback to remember the platform which was provided. At this moment I do not know from which platform the data is coming from.</p>
  <p>Any ideas how a parameter can be remembered in the response?</p>