_updateItemStyle(el, opacity, zIndex, transform) {
      el.style[this.xform] = transform;
      el.style.zIndex = zIndex;
      el.style.opacity = opacity;
      el.style.visibility = 'visible';
    }
Cycle to target
@param {Element} el
@param {Number} opacity
@param {Number} zIndex
@param {String} transform