code: async def open_session(
              self,
              app: 'Quart',
              request: BaseRequestWebsocket,
      ) -> Optional[SecureCookieSession]:
          
          signer = self.get_signing_serializer(app)
          if signer is None:
              return None
  
          cookie = request.cookies.get(app.session_cookie_name)
          if cookie is None:
              return self.session_class()
          try:
              data = signer.loads(
                  cookie, max_age=app.permanent_session_lifetime.total_seconds(),
              )
              return self.session_class(**data)
          except BadSignature:
              return self.session_class()
docs: Open a secure cookie based session.
  
          This will return None if a signing serializer is not availabe,
          usually if the config SECRET_KEY is not set.