d value for ' + id);
            return value;
        }

        /**
   * As above, but also makes sure that the value is a string.
   * @param {string} id The key that identifies the desired string.
   * @return {string} The corresponding string value.
   */
        getString(id) {
            const value = this.getValue(id);
            expectIsType(id, value, 'string');
            return /** @type {string} */ (value);
        }

        /**
   * Returns a formatted localized string where $1 to $9 are r