code: function getRevealSize() {
          var carousel = this, isVertical, sz;
  
          isVertical = carousel.get("isVertical");
          sz  = getCarouselItemSize.call(carousel,
                  isVertical ? "height" : "width");
          return (sz * carousel.get("revealAmount") / 100);
      }
docs: Return the size of a part of the item (reveal).
  
  @method getRevealSize
  @private