title: Is-there an opposite of the `race` operator in RxJS?
body: <p>I have two observables and I want listen to the one that emits its first value last, is there an operator for this ? Something like that :</p>
  
  <pre><code>let obs1 = Rx.Observable.timer(500,500);
  let obs2 = Rx.Observable.timer(1000,1000); // I want the values from this one
  let sloth = Rx.Observable.sloth(obs1,obs2);
  </code></pre>
  
  <p>where the <code>sloth</code> observable would emit the values from <code>obs2</code> as it is the one who emits its first value last.</p>
  
  <p>If that's not the case, is there any other way ?</p>