PDF.js version: 3.5.141

These two properties should be marked as not mandatory as they are initialized if not present
const firstPageView = this._pages[0];
    for (let i = 1, ii = this._pages.length; i < ii; ++i) {
      const pageView = this._pages[i];
      if (
        pageView.width !== firstPageView.width ||
        pageView.height !== firstPageView.height
      ) {
        return false;
      }
    }
    return true;
  }
  /**
   * Returns sizes of the pages.
   * @returns {Array} Array of objects with width/height/rotation fields.
   */
  getPagesOverview() {