title: instanceof check in EL expression language
body: <p>Is there a way to perform an <code>instanceof</code> check in EL?</p>
  
  <p>E.g.</p>
  
  <pre><code>&lt;h:link rendered="#{model instanceof ClassA}"&gt;      
      #{errorMessage1}
  &lt;/h:link&gt;
  &lt;h:link rendered="#{model instanceof ClassB}"&gt;      
      #{errorMessage2}
  &lt;/h:link&gt;
  </code></pre>