  - Open https://mozilla.github.io/pdf.js/web/viewer.html
  - Open a pdf with some XFA (for example the on in https://github.com/mozilla/pdf.js/issues/13679#issue-937616350)

The pdf is not correctly displayed because `enableXfa` is false.

@Snuffleupagus, the pref is set to true in Firefox nightly, is there anything blocking setting it to true in the web viewer ?  
userOptions[name] = value;
  }
  static setAll(options) {
    for (const name in options) {
      userOptions[name] = options[name];
    }
  }
  static remove(name) {
    delete userOptions[name];
  }
}
export { AppOptions, compatibilityParams, OptionKind };