public function post(array $doc)
    {
        $context = array('http' => array());

        $context['http']['method'] = 'POST';
        $context['http']['header'] = 'Content-Type: application/json';
        $context['http']['content'] = json_encode($doc);

        list($status, $response) = $this->sendRequest('', $context);

        if ($status != 201) {
            throw new Exception\Response('POST - Unknown response status.');
        }

        if (isset($response['id'])) {
            return array('_id' => $response['id'], '_rev' => $response['rev']);
        } else {
            return $response;
        }
    }