title: Splitting List into sublists along elements
body: <p>I have this list (<code>List&lt;String&gt;</code>):</p>
  
  <pre><code>["a", "b", null, "c", null, "d", "e"]
  </code></pre>
  
  <p>And I'd like something like this:</p>
  
  <pre><code>[["a", "b"], ["c"], ["d", "e"]]
  </code></pre>
  
  <p>In other words I want to split my list in sublists using the <code>null</code> value as separator, in order to obtain a list of lists (<code>List&lt;List&lt;String&gt;&gt;</code>). I'm looking for a Java 8 solution. I've tried with <code>Collectors.partitioningBy</code> but I'm not sure it is what I'm looking for. Thanks!</p>