PDF.js version: 3.5.141

These two properties should be marked as not mandatory as they are initialized if not present
if (visible.first?.id === 1) {
      return true;
    } else if (visible.last?.id === this.pagesCount) {
      return false;
    }
    switch (this._scrollMode) {
      case ScrollMode.PAGE:
        return this.#scrollModePageState.scrollDown;
      case ScrollMode.HORIZONTAL:
        return this.scroll.right;
    }
    return this.scroll.down;
  }
  forceRendering(currentlyVisiblePages) {