constructor(harness) {
    /** @private {?shaka.media.PlayRateController.Harness} */
    this.harness_ = harness;

    /** @private {boolean} */
    this.isBuffering_ = false;

    /** @private {number} */
    this.rate_ = this.harness_.getRate();

    /** @private {number} */
    this.pollRate_ = 0.25;

    /** @private {shaka.util.Timer} */
    this.timer_ = new shaka.util.Timer(() => {
      this.harness_.movePlayhead(this.rate_ * this.pollRate_);
    });
  }
@param {shaka.media.PlayRateController.Harness} harness