docs: def init_app(self, app):
          '''Initalizes the application with the extension.
          
          :param app: The Flask application object.
          '''
          self.app = app
          self._session_conf = app.config.get('BEAKER_SESSION', {
              'session.type': 'file',
              'session.data_dir': '/tmp/session/data',
              'session.lock_dir': '/tmp/session/lock'
          })
          app.wsgi_app = SessionMiddleware(app.wsgi_app, self._session_conf)
          app.session_interface = BeakerSessionInterface()