docs: def configure_app(app, config=None, config_obj=None):
      """Configure application instance.
  
      Args:
          app (Flask): initialized Flask app instance
          config (Optional[path]): path to a Python module config file
          config_obj (Optional[class]): Python config object
      """
      app.config.from_object(config_obj or BaseConfig)
      if config is not None:
          app.config.from_pyfile(config)