title: For Vaadin Combo Box I need to display one value and set another value
body: <p>I have Vaadin Combo Box with below items</p>
  
  <pre><code>Application
  Federation
  Innovation
  </code></pre>
  
  <p>When the user selects Application from the dropdown box I need to set APP in the similar way </p>
  
  <pre><code>Federation - FED
  Innovation - INV
  </code></pre>
  
  <p>So when I fetch the need only short code of it not the entire name. How to achieve that?.</p>