art"><code>new Observable.periodic(const Duration(milliseconds: 100), (int i) =&gt; i)
  .windowTest((i) =&gt; i % 2 == 0)
  .asyncMap((stream) =&gt; stream.toList())
  .listen(print); // prints [0], [1, 2] [3, 4] [5, 6] ...
</code></pre>
    </section>
    
    <section class="summary source-code" id="source">
      <h2><span>Implementation</span></h2>
      <pre class="language-dart"><code class="language-dart">Observable&lt;Stream&lt;T&gt;&gt; windowTest(bool onTestHandler(T event)) =&gt;
    transform(W