nextPage() {
    const currentPageNumber = this._currentPageNumber,
      pagesCount = this.pagesCount;

    if (currentPageNumber >= pagesCount) {
      return false;
    }
    const advance =
      this._getPageAdvance(currentPageNumber, /* previous = */ false) || 1;

    this.currentPageNumber = Math.min(currentPageNumber + advance, pagesCount);
    return true;
  }
Go to the next page, taking scroll/spread-modes into account.
@returns {boolean} Whether navigation occurred.