title: RxJava collect AMPQ event in an Observable and subscribe with a buffer
body: <p>I have to collect some AMPQ events and then print them every 10 sec using a buffer. </p>
  
  <pre><code>private Observable&lt;Event&gt; obs = Observable.empty(); 
  private final Disposable disposable = obs.buffer(10, SECONDS)
                                .retry(t -&gt; true)
                                .subscribe(System.out::println);
  
  @Override
  public void handle(final Event event, final MessageContext context) throws MessageConsumptionException {
        obs = obs.concatWith(Observable.just(event));
  }
  </code></pre>
  
  <p><em>Event</em> is the message and <em>void handle</em> is the consumer. </p>
  
  <p>I debug this code and it print only an empty list, and it makes sense because <em>obs</em> is empty.</p>
  
  <p>How can I add (concat?) events into this Observable and execute the <em>disposable</em> continually?
  Thanks.</p>