public function getColumns()
    {
        $session = request()->session();
        $key     = $this->key();
        if (!$session->has($key)) {
            return $this->columns;
        }
        $config = $session->get($key);
        foreach ($this->columns as $index => $column) {
            if (!isset($config[$index])) {
                continue;
            }
            $column->visible = $config[$index];
        }

        return $this->columns;
    }