private function handle_patch($data)
 {
     $profile = UserBackend::fetch_user_profile($this->params['id']);
     $displayname = $profile->getDisplayName();
     $username = $profile->getUsername();
     if (isset($data->{"display-name"})) {
         $displayname = $data->{"display-name"};
     }
     if (isset($data->{"user-name"})) {
         $username = $data->{"user-name"};
     }
     $profile = new UserProfile($profile->getUserId(), $username, $displayname);
     UserBackend::update_user_profile($profile);
     return $this->handle_get($data);
 }