code: function () {
          var self = this, layout = self._layout, prefix = self.classPrefix;
  
          self.preRender();
          layout.preRender(self);
  
          return (
            '<fieldset id="' + self._id + '" class="' + self.classes + '" hidefocus="1" tabindex="-1">' +
            (self.settings.title ? ('<legend id="' + self._id + '-title" class="' + prefix + 'fieldset-title">' +
              self.settings.title + '</legend>') : '') +
            '<div id="' + self._id + '-body" class="' + self.bodyClasses + '">' +
            (self.settings.html || '') + layout.renderHtml(self) +
            '</div>' +
            '</fieldset>'
          );
        }
docs: Renders the control as a HTML string.
  
  @method renderHtml
  @return {String} HTML representing the control.