title: Restart BehaviorSubject after an error
body: <p>Wanted behavior:</p>
  
  <pre><code>subject = BehaviorSubject.create(1);
  subject.subscribe(number -&gt; print(number), error -&gt; print(error));
  
  subject.onNext(2);
  subject.onNext(3);
  subject.onError(new RuntimeException("I'm an error"));
  subject.onNext(4);
  subject.onNext(5);
  </code></pre>
  
  <p>With this output:</p>
  
  <pre><code>1
  2
  3
  I'm an error
  4
  5
  </code></pre>
  
  <p>My problem is that <code>onNext</code> after <code>onError</code> isn't working (and this is intended, following <code>RxJava</code> rules), but I'll need subject to be resilient to errors, while also passing them down the stream (to show the user some feedback).</p>
  
  <p>Is there a way to do this?</p>