public function save($columns = ['*'])
    {
        $columns = $columns ? (array)$columns : ['*'];

        if ($this->saving() === false) {
            return false;
        }

        $this->fillTimestamp();

        $this->_dal->put($columns);

        $this->_exist = true;

        // self::cache()->put($id, $this);

        if ($this->saved() === false) {
            return false;
        }

        return true;
    }