https://github.com/mozilla/pdf.js/blob/0df1a5661958df0c4ed2f73b0f3266d825c5c280/src/display/api.js#L710-L719
The return type signature `@returns {Promise<{num: number, gen: number}>}` is mismatched with its definition. (should be `@returns {Promise<number>}`)
constructor(pageIndex, pageInfo, transport, ownerDocument, pdfBug = false) {
    this._pageIndex = pageIndex;
    this._pageInfo = pageInfo;
    this._ownerDocument = ownerDocument;
    this._transport = transport;
    this._stats = pdfBug ? new StatTimer() : null;
    this._pdfBug = pdfBug;
    this.commonObjs = transport.commonObjs;
    this.objs = new PDFObjects();
    this.cleanupAfterRender = false;
    this.pendingCleanup = false;
    this._intentStates = new Map();
    this.destroyed = false;
  }
  /**
   * @type {number} Page number of the page. First page is 1.
   */
  get pageNumber() {