code: def verify_refresh_request(request):
      
      jwtauth_settings = request.app.settings.jwtauth.__dict__.copy()
      identity_policy = JWTIdentityPolicy(**jwtauth_settings)
  
      return identity_policy.verify_refresh(request)
docs: Wrapper around JWTIdentityPolicy.verify_refresh which verify
      if the request to refresh the token is valid.
      If valid it returns the userid which can be used to create to
      create an updated identity with ``remember_identity``.
      Otherwise it raises an exception based on InvalidTokenError.
  
      :param request: request object
      :type request: :class:`morepath.Request`
      :returns: userid
      :raises: InvalidTokenError, ExpiredSignatureError, DecodeError,
          MissingRequiredClaimError