title: Angular 2 repeat the forkJoin 5 seconds after it's completed
body: <p>I would like to repeat my forkJoin method every 5 seconds. The 5 second timer  should be started once the forkJoin completed and returned the result; </p>
  
  <p>This is my current forkJoin:</p>
  
  <pre><code>  let getResult1 = this.myService.GetResult1(param1, param2);       // retrun Observable&lt;Result1&gt;
        let getResult2 = this.myService.GetResult2(param1, param3,param4);// retrun Observable&lt;Result2&gt;
  
         Observable.forkJoin(getResult1, getResult2)
              .subscribe(results =&gt; {
                this.result1 = results[0];
                this.result2 = results[1];
                .. start counting 5 seconds and then repeat this again and again
              },
              error =&gt; this.handleError(error));
  </code></pre>
  
  <p>Timeline i want:</p>
  
  <p>Time(s): 0 - - 1 - - 2 - - 3 - - 4 - - 5 - - 6</p>
  
  <p>Action:  Req - Res - - -  - - - - - - - - - -Req-... </p>
  
  <p>Wait:          | wait for 5 seconds -------> |</p>