code: function apply(slides) {
        for (var i = 0, len = slides.length; i < len; i++) {
          var style = slides[i].style;
          var direction = Components.Direction.value;
  
          if (i !== 0) {
            style[MARGIN_TYPE[direction][0]] = this.value / 2 + 'px';
          } else {
            style[MARGIN_TYPE[direction][0]] = '';
          }
  
          if (i !== slides.length - 1) {
            style[MARGIN_TYPE[direction][1]] = this.value / 2 + 'px';
          } else {
            style[MARGIN_TYPE[direction][1]] = '';
          }
        }
      }
docs: Applies gaps between slides. First and last
  slides do not receive it's edge margins.
  
  @param {HTMLCollection} slides
  @return {Void}