public function nth($index, $object = false)
    {
        $this->prepare();

        $data = $this->_map;
        $total_elm = count($data);
        $idx =  abs($index);

        if (!is_integer($index) || $total_elm < $idx || $index == 0 || !is_array($this->_map)) {
            return null;
        }

        if ($index > 0) {
            $result = $data[$index - 1];
        } else {
            $result = $data[$this->count() + $index];
        }

        return $this->prepareResult($result, $object);
    }