code: function () {
      var data = {};
      var trackedControllerEls = this.trackedControllerEls;
  
      if (this.isRecording) { return; }
  
      // Camera.
      data.camera = this.cameraEl.components['motion-capture-recorder'].getJSONData();
  
      // Tracked controls.
      Object.keys(trackedControllerEls).forEach(function getControllerData (id) {
        data[id] = trackedControllerEls[id].components['motion-capture-recorder'].getJSONData();
      });
  
      return data;
    }
docs: Gather the JSON data from the camera and tracked controls motion-capture-recorder
  components. Combine them together, keyed by the (active) `camera` and by the
  tracked controller IDs.