title: How to use data on _trigger for custom widget?
body: <p>I have a widget created using jquery ui widget factory. I'm trying to pass some data to my custom event like this</p>
  
  <pre><code>this._trigger('myCustomEvent', ['Test', 'Test2']);
  </code></pre>
  
  <p>but on my handler I'm not sure how to access custom parameters</p>
  
  <pre><code>onMyCustomEvent: function(event, ui) {
     ...
  }
  </code></pre>
  
  <p>I've tried adding parameter to my handler</p>
  
  <pre><code>onMyCustomEvent': function(event, ui, param1, param2) {...}
  </code></pre>
  
  <p>but that didn't work: param1 and param2 are <code>undefined</code></p>