Sokil\Mongo\Structure::has PHP 메소드

    public function has($selector)
    {
        $pointer =& $this->data;
        foreach (explode('.', $selector) as $field) {
            if (!array_key_exists($field, $pointer)) {
                return false;
            }
            $pointer =& $pointer[$field];
        }
        return true;
    }