code: function copyAttributes(source, destination, extraAttrs) {
          var copiedAttrs = $mdUtil.prefixer([
            'ng-if', 'ng-click', 'ng-dblclick', 'aria-label', 'ng-disabled', 'ui-sref',
            'href', 'ng-href', 'rel', 'target', 'ng-attr-ui-sref', 'ui-sref-opts', 'download'
          ]);
  
          if (extraAttrs) {
            copiedAttrs = copiedAttrs.concat($mdUtil.prefixer(extraAttrs));
          }
  
          angular.forEach(copiedAttrs, function(attr) {
            if (source.hasAttribute(attr)) {
              destination.setAttribute(attr, source.getAttribute(attr));
              source.removeAttribute(attr);
            }
          });
        }
docs: Copies attributes from a source element to the destination element
  By default the function will copy the most necessary attributes, supported
  by the button executor for clickable list items.
  @param source Element with the specified attributes
  @param destination Element which will retrieve the attributes
  @param extraAttrs Additional attributes, which will be copied over.