GraphAware\Reco4PHP\Util\NodeProxy::value PHP Метод

    public function value($key, $default = null)
    {
        if (!$this->containsKey($key) && 1 === func_num_args()) {
            throw new \InvalidArgumentException(sprintf('This node doesn\'t contain the "%s" property'), $key);
        }
        return $this->containsKey($key) ? $this->properties[$key] : $default;
    }