public function getPropertyHook($ns, $name, $user)
    {
        if ($this->getNext() !== null) {
            $o = $this->getNext()->getPropertyHook($ns, $name, $user);
            if ($o !== null) {
                return $o;
            }
        }

        if (self::$project !== null && StringHelper::startsWith('toString:', $name)) {
            $name = StringHelper::substring($name, strlen('toString:'));
            $v = self::$project->getReference($name);
            return ($v === null) ? null : (string) $v;
        }

        return null;
    }