append(holderElement) {
    this.holderElement = holderElement;
    this.container.style.transformOrigin = '0 0'; // Slide appended to DOM

    if (!this.data) {
      return;
    }

    this.calculateSize();
    this.load();
    this.updateContentSize();
    this.appendHeavy();
    this.holderElement.appendChild(this.container);
    this.zoomAndPanToInitial();
    this.pswp.dispatch('firstZoomPan', {
      slide: this
    });
    this.applyCurrentZoomPan();
    this.pswp.dispatch('afterSetContent', {
      slide: this
    });

    if (this.isActive) {
      this.activate();
    }
  }
Appends slide content to DOM

@param {HTMLElement} holderElement