
   *     var value = loadTimeData.data()['key'];
   *
   * @param {Object} value The de-serialized page data.
   */
        set data(value) {
            expect(!this.data_, 'Re-setting data.');
            this.data_ = value;
        }

        /**
   * Returns a JsEvalContext for |data_|.
   * @returns {JsEvalContext}
   */
        createJsEvalContext() {
            return new JsEvalContext(this.data_);
        }

        /**
   * @param {string} id An ID of a value that might exist.
   * @return {boole