public function returnOriginalData($key = null)
    {
        $this->_prepareData($key);

        $mergedData = array_merge($this->_DATA, $this->_originalDATA);
        $data       = $this->_removeNewKeys($mergedData);

        if (array_key_exists($key, $data)) {
            return $data[$key];
        }

        return null;
    }