code: function PosePredictor(predictionTimeS, isDebug) {
    this.predictionTimeS = predictionTimeS;
    this.isDebug = isDebug;
  
    // The quaternion corresponding to the previous state.
    this.previousQ = new MathUtil.Quaternion();
    // Previous time a prediction occurred.
    this.previousTimestampS = null;
  
    // The delta quaternion that adjusts the current pose.
    this.deltaQ = new MathUtil.Quaternion();
    // The output quaternion.
    this.outQ = new MathUtil.Quaternion();
  }
docs: Given an orientation and the gyroscope data, predicts the future orientation
  of the head. This makes rendering appear faster.
  
  Also see: http://msl.cs.uiuc.edu/~lavalle/papers/LavYerKatAnt14.pdf
  
  @param {Number} predictionTimeS time from head movement to the appearance of
  the corresponding image.