public function offset($offset)
    {
        if ($this->queryType !== self::QUERY_SELECT) {
            $this->exception = new QueryException("Offset can only be applied on SELECT mode!", 0, $this->exception);
            return $this;
        }
        if (! is_int($offset) || $offset < 0) {
            $this->exception = new QueryException("Offset value should be an positive integer!", 0, $this->exception);
            return $this;
        }
        $this->limitOffset = intval($offset);

        return $this;
    }