constructor(maxRequestsPerMinute) {
    super();

    /**
     * The timestamps of the previously processed requests.
     * @type {!Array.<number>}
     * @private
     */
    this.processedRequests_ = [];

    /**
     * The maximum allowed requests per minute.
     * @type {number}
     * @private
     */
    this.maxRequestsPerMinute_ = maxRequestsPerMinute;
  }
@param {number} maxRequestsPerMinute The maximum allowed requests per
    minute.