title: In PrimeNG how to apply conditional coloring to rows in tree table component
body: <p>I am new to PrimeNG, and using a tree table component in my angular 2 application. </p>
  
  <p>I want to apply the entire row (tr) with different style based on conditions. I tried ngStyle and ngClass. But it is not working.</p>
  
  <pre><code>&lt;p:treetable id="coloring" var="car" [value]="{treeTableController}"
  [ngStyle] ="{{car.year le 1975 ? 'colored' : null}}"&gt;
  &lt;p:columnheaderText="Year"&gt;{car.year}&lt;/p:column&gt;
  &lt;p:columnheaderText="Name"&gt;{car.name}&lt;/p:column&gt;
  &lt;/p:treetable&gt;
  </code></pre>
  
  <p>Any help is highly appreciated.</p>