public function next()
    {
        if ($this->limit && $this->currentPos >= $this->limit) { // it won't go further than the selected limit
            return null;
        }
        $oldLimit = $this->limit;
        $oldOffset = $this->offset;
        $this->limit = 1;
        $this->offset += $this->currentPos;
        $rows = $this->get();
        $this->limit = $oldLimit;
        $this->offset = $oldOffset;
        $this->currentPos++;
        return isset($rows[0]) ? $rows[0] : null;
    }