For reference:
https://github.com/mozilla/pdf.js/issues/15571#issuecomment-1278141781
this.#currentPageIndex = pageNumber - 1;
  }
  focusMainContainer() {
    this.#container.focus();
  }
  #addKeyboardManager() {
    
    
    this.#container.addEventListener("keydown", this.#boundKeydown);
  }
  #removeKeyboardManager() {
    this.#container.removeEventListener("keydown", this.#boundKeydown);
  }
  #addCopyPasteListeners() {
    document.addEventListener("copy", this.#boundCopy);
    document.addEventListener("cut", this.#boundCut);
    document.addEventListener("paste", this.#boundPaste);
  }
  #removeCopyPasteListeners() {
    document.removeEventListener("copy", this.#boundCopy);
    document.removeEventListener("cut", this.#boundCut);
    document.removeEventListener("paste", this.#boundPaste);
  }
  /**
   * Copy callback.
   * @param {ClipboardEvent} event
   */
  copy(event) {