code: def setup(self, app):
          
          super().setup(app)
  
          if self.cfg.secret == 'InsecureSecret':
              app.logger.warning(
                  'Use insecure secret key. Change SESSION_SECRET option in configuration.')
  
          self._user_loader = asyncio.coroutine(lambda id_: id_)  # noqa
  
          app.on_response_prepare.append(self.save)
  
          if self.cfg.auto_load:
              app.middlewares.append(self._middleware)
docs: Initialize the plugin.