title: How can i access my Objects in a vaadin tree?
body: <p>I`ve added my own objects into a vaadin tree like this:</p>
  
  <pre><code>Item item = container.addItem(planet); //where planet is from class Planet
  </code></pre>
  
  <p>If I get it right, only the string taken from planet.toString() will be added to my tree.</p>
  
  <p>Now I need to access several methods/attributes of my object (e.g. getMoons() or getPlanetID()). How can I access my object by selecting this planet in my tree (via getValue() in my valueChanged-event) ?</p>