PDF.js version: 3.5.141

These two properties should be marked as not mandatory as they are initialized if not present
return this.isInPresentationMode
      ? false
      : this.container.scrollWidth > this.container.clientWidth;
  }
  get isVerticalScrollbarEnabled() {
    return this.isInPresentationMode
      ? false
      : this.container.scrollHeight > this.container.clientHeight;
  }
  _getVisiblePages() {
    const views =
        this._scrollMode === ScrollMode.PAGE
          ? this.#scrollModePageState.pages
          : this._pages,
      horizontal = this._scrollMode === ScrollMode.HORIZONTAL,
      rtl = horizontal && this._isContainerRtl;
    return getVisibleElements({
      scrollEl: this.container,
      views,
      sortByVisibility: true,
      horizontal,
      rtl,
    });
  }
  /**
   * @param {number} pageNumber
   */
  isPageVisible(pageNumber) {