code: function (element) {
          var boundingClientRect = element[0].getBoundingClientRect();
          return {
            width: boundingClientRect.width || element.prop('offsetWidth'),
            height: boundingClientRect.height || element.prop('offsetHeight'),
            top: boundingClientRect.top + ($window.pageYOffset || $document[0].documentElement.scrollTop),
            left: boundingClientRect.left + ($window.pageXOffset || $document[0].documentElement.scrollLeft)
          };
        }
docs: Provides read-only equivalent of jQuery's offset function:
  http://api.jquery.com/offset/