resolve(id) {
    const Class = shaka.ui.Localization;
    const FakeEvent = shaka.util.FakeEvent;

    /** @type {string} */
    const result = this.currentMap_.get(id);

    // If we have a result, it means that it was found in either the current
    // locale or one of the fall-backs.
    if (result) {
      return result;
    }

    // Since we could not find the result, it means it is missing from a large
    // number of locales. Since we don't know which ones we actually checked,
    // just tell them the preferred locale.

    const data = new Map()
        // Make a copy to avoid leaking references.
        .set('locales', Array.from(this.currentLocales_))
        .set('missing', id);
    this.dispatchEvent(new FakeEvent(Class.UNKNOWN_LOCALIZATION, data));

    return '';
  }
Request the localized string under the given id. If there is no localized
version of the string, then the fallback localization will be given
("en" version). If there is no fallback localization, a non-null empty
string will be returned.

@param {string} id The id for the localization entry.
@return {string}
@export