zoomIn() {
    if (!this.ws_.options.showIndex) return;
    this.enable();
    const currentId = this.ws_.currentSlide_.el.id;
    const zoomedCurrent = this.zws_.el
      .querySelector(`.${CLASSES.WRAP}.${CLASSES.CURRENT}`);

    if (zoomedCurrent) {
      zoomedCurrent.classList.remove(CLASSES.CURRENT);
    }

    const actualCurrent = this.zws_.el
      .querySelector(`#zoomed-${currentId}`);
    actualCurrent.classList.add(CLASSES.CURRENT);

    this.isZoomed_ = true;
    document.documentElement.classList.add(CLASSES.ZOOM_ENABLED);

    setTimeout(() => {
      this.ws_.disable();
      this.zws_.el.classList.add('in');
      const wrapCSS = window.getComputedStyle(this.zws_.grid);
      const scrollingElement = document.body;

      scrollTo(actualCurrent.parentNode.offsetTop
        + DOM.parseSize(wrapCSS.paddingTop), 50, () => {}, scrollingElement);
    }, 50);
  }
Zoom In the slider, scales the slides and uses a grid layout to show them.