title: Parsing json to Nattable
body: <p>I have to parse a Json file and show it into a Nattable. 
  Using <a href="http://www.vogella.com/tutorials/NatTableDataSources/article.html" rel="nofollow noreferrer">this</a> tutorial i am able to parse json and display in Nattable.<a href="https://i.stack.imgur.com/FvxX9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FvxX9.png" alt="enter image description here"></a></p>
  
  <p>But as shown in screenshot <strong>for cat column</strong> its showing list values as it is .
  Is there a way from which i can show list values as Dropdown.</p>