title: How to return observable from subscribe?
body: <p>For example, I have code like this:</p>
  
  <pre><code>// angular service post method
  postUser(): Observable&lt;User&gt; {
     this.tokenService.getToken().subscribe(token =&gt; {
         // need to return this observable
         return this.http.post&lt;User&gt;(url, {token});
     })
  }
  </code></pre>