code: function (spinner) {
      var $spinner = $(spinner);
      var layer;
      if ($spinner.hasClass('mdui-spinner-colorful')) {
        layer = layerHTML('1') + layerHTML('2') + layerHTML('3') + layerHTML('4');
      } else {
        layer = layerHTML();
      }
  
      $spinner.html(layer);
    }
docs: 填充 HTML
  @param spinner