code: function setGazeCallback(gazeFunction){
  
      if (typeof(gazeFunction) == 'function'){
  
          gazeCollector.setGazeCallback(gazeFunction);
          callbacks.gazeCallback = gazeFunction;
  
      }
      else
          logger.warn('Trying to set a non function object as gaze callback');
      
  }
docs: Sets the function to call when calculating gaze hit point
  @memberof DataCollector
  @param {function} gazeFunction