title: GWT, passing an ArrayList to JSNI
body: <p>In my GWT application I have a javascript function wich require an array of array as argument. I get the data using RPC, so I get a List&lt; List > from my database. I need this because I have to fill a kind of tree view. For example, I get this from my RPC call: {"A", "A1", "A2"}, {"B", "B1"}, and I have to pass this to my javascript function: [["A", "A1", "A2"], ["B", "B1"]]. In my interface I want to show:</p>
  
  <pre><code>A+
    A1
    A2
  B+
    B1
  </code></pre>
  
  <p>How can I pass it to my javascript function using JSNI?</p>