docs: function FusionPoseSensor(kFilter, predictionTime, yawOnly, isDebug) {
    this.yawOnly = yawOnly;
  
    this.accelerometer = new MathUtil.Vector3();
    this.gyroscope = new MathUtil.Vector3();
  
    this.filter = new ComplementaryFilter(kFilter, isDebug);
    this.posePredictor = new PosePredictor(predictionTime, isDebug);
  
    this.isFirefoxAndroid = Util.isFirefoxAndroid();
    this.isIOS = Util.isIOS();
    // Chrome as of m66 started reporting `rotationRate` in degrees rather
    // than radians, to be consistent with other browsers.
    // https://github.com/immersive-web/cardboard-vr-display/issues/18
    let chromeVersion = Util.getChromeVersion();
    this.isDeviceMotionInRadians = !this.isIOS && chromeVersion && chromeVersion < 66;
    // In Chrome m65 there's a regression of devicemotion events. Fallback
    // to using deviceorientation for these specific builds. More information
    // at `Util.isChromeWithoutDeviceMotion`.
    this.isWithoutDeviceMotion = Util.isChromeWithoutDeviceMotion();
  
    this.filterToWorldQ = new MathUtil.Quaternion();
  
    // Set the filter to world transform, depending on OS.
    if (Util.isIOS()) {
      this.filterToWorldQ.setFromAxisAngle(new MathUtil.Vector3(1, 0, 0), Math.PI / 2);
    } else {
      this.filterToWorldQ.setFromAxisAngle(new MathUtil.Vector3(1, 0, 0), -Math.PI / 2);
    }
  
    this.inverseWorldToScreenQ = new MathUtil.Quaternion();
    this.worldToScreenQ = new MathUtil.Quaternion();
    this.originalPoseAdjustQ = new MathUtil.Quaternion();
    this.originalPoseAdjustQ.setFromAxisAngle(new MathUtil.Vector3(0, 0, 1),
                                             -window.orientation * Math.PI / 180);
  
    this.setScreenTransform_();
    // Adjust this filter for being in landscape mode.
    if (Util.isLandscapeMode()) {
      this.filterToWorldQ.multiply(this.inverseWorldToScreenQ);
    }
  
    // Keep track of a reset transform for resetSensor.
    this.resetQ = new MathUtil.Quaternion();
  
    this.orientationOut_ = new Float32Array(4);
  
    this.start();
  }