title: Callback function on addClass not working
body: <p>I want the browser to focus on the input after clicking the focus button. </p>
  
  <p>But before that I want it to add a class first and then focus. Is this possible? Or can I only use callback functions on 'animations' like hide, click etc.</p>
  
  <p>I've created a jfiddle: <a href="https://jsfiddle.net/6ktgc4h9/5/" rel="nofollow">https://jsfiddle.net/6ktgc4h9/5/</a></p>
  
  <pre><code>$('.input').hide();
  
  $('.focus').click(function()
  {
      $('.input').show();
  
    $('input').addClass('test', function()
    {
          $('.search').focus();
    });
  })
  </code></pre>