code: function getUnboundedScrollPosition(scrollable) {
    if (scrollable.Window && scrollable instanceof scrollable.Window) {
      return {
        x: scrollable.pageXOffset || scrollable.document.documentElement.scrollLeft,
        y: scrollable.pageYOffset || scrollable.document.documentElement.scrollTop
      };
    }
    return {
      x: scrollable.scrollLeft,
      y: scrollable.scrollTop
    };
  }
docs: Gets the scroll position of the supplied element or window.
  
  The return values are unbounded, unlike `getScrollPosition`. This means they
  may be negative or exceed the element boundaries (which is possible using
  inertial scrolling).
  
  @param {DOMWindow|DOMElement} scrollable
  @return {object} Map with `x` and `y` keys.