initTrackingValues() {
    this.milestoneValues = [25, 50, 75, 100];
    this.milestones = [];
    this._properties.startTime = null;
  }
/**
   * Reset the tracking milestones and clear out start time.
   */
Reset the tracking milestones and clear out start time.
Reset the tracking milestones and clear out start time .
initTrackingValues() {
    this.milestoneValues = [25, 50, 75, 100];
    this.milestones = [];
    this._properties.startTime = null;
  }
initTrackingValues ( ) { this . milestoneValues = [ 25 , 50 , 75 , 100 ] ; this . milestones = [ ] ; this . _properties . startTime = null ; }
Reset the tracking milestones and clear out start time.
Reset the tracking milestones and clear out start time .