function random(int $num = 1) {
        $rand = \array_rand($this->data, $num);
        if(!\is_array($rand)) {
            $rand = array($rand);
        }
        
        $col = new self();
        foreach($rand as $key) {
            $col->set($key, $this->data[$key]);
        }
        
        return $col;
    }