title: how to return an empty observable
body: <p>according to this answer <a href="https://stackoverflow.com/questions/38548407/how-to-return-an-empty-observable-in-rxjs">How to return an empty observable in rxjs</a> i have tried all of it but it did not work for me </p>
  
  <p>here is my code</p>
  
  <pre><code>post(url):Observalbe&lt;any&gt;{
     if(this.holder.nullConnection()){ //checking internet connection
        //return empty observalbe
        return Observable.empty() ;
      }else{
        return this.http.post(this.configurator.restServerBaseUrl+url,data)
        .map((result:Response)=&gt; {
          return result.json()
        })
      }
  }
  </code></pre>
  
  <p>i have tried almost all the answers as per the stack question you can see above any help to return an empty obserable.</p>