title: Split CellList into Columns, sorted vertically
body: <p>I want to split the <code>CellList</code>'s contents <strong>vertically</strong> across three columns. See this example below (for a List containing the letters A to H).</p>
  
  <pre><code>A D G
  B E H
  C F
  </code></pre>
  
  <p>I have a single <code>CellList cell</code> that contains data provided by an <code>AsyncDataProvider&lt;String&gt;</code>.</p>
  
  <p>The <code>CellList</code> is being displayed in a UiBinder Template. What's the easiest way to do this? So far I've only come up with:</p>
  
  <ol>
  <li>Use 3 CellLists and split it manually with 3 AsyncDataProviders that you populate</li>
  <li>Use a CellTable and populate the columns weirdly</li>
  <li>Create a custom CellList that inserts random breakers</li>
  </ol>
  
  <p>These are all pretty tedious and seem unintuitive. Is there an easier way to do this?</p>