title: How can I set properties for ui Backbone element?
body: <p>How can I set properties (attributes) for "uploadButton"?</p>
  
  <pre><code>return Marionette.ItemView.extend({
    ui: {
         "uploadButton": "ui-button green"
      }
  });
  
  this.ui.uploadButton. - and???
  </code></pre>