docs: def remember(self, response, request, identity):
          """Remember identity on response.
  
          Implements ``morepath.App.remember_identity``, which is called
          from user login code.
  
          Create a JWT token and return it as the Authorization field of the
          response header.
  
          :param response: response object on which to store identity.
          :type response: :class:`morepath.Response`
          :param request: request object.
          :type request: :class:`morepath.Request`
          :param identity: identity to remember.
          :type identity: :class:`morepath.Identity`
          """
          claims = identity.as_dict()
          userid = claims.pop('userid')
          claims_set = self.create_claims_set(request, userid, claims)
          token = self.encode_jwt(claims_set)
          response.headers['Authorization'] = '%s %s' % (self.auth_header_prefix,
                                                         token)