public function createTimestampWatermark($name, $options = array())
    {
        list($config, $timezone, $alpha, $fontFamily, $fontSizeInPoint,
            $fontColor, $backgroundColor, $verticalAlignment, $horizontalAlignment,
            $verticalOffsetInPixel, $horizontalOffsetInPixel) = $this->parseOptions(
            $options,
            'config',
            'timezone',
            'alpha',
            'fontFamily',
            'fontSizeInPoint',
            'fontColor',
            'backgroundColor',
            'verticalAlignment',
            'horizontalAlignment',
            'verticalOffsetInPixel',
            'horizontalOffsetInPixel'
        );

        if (empty($name)) {
            throw new BceClientException("The parameter name "
                . "should NOT be null or empty string");
        }

        $body = array(
            'name' => $name,
        );

        if ($timezone !== null) {
            $body['timezone'] = $timezone;
        }
        if ($alpha !== null) {
            $body['alpha'] = $alpha;
        }

        $font = array();
        if ($fontFamily !== null) {
            $font['family'] = $fontFamily;
        }
        if ($fontSizeInPoint !== null) {
            $font['sizeInPoint'] = $fontSizeInPoint;
        }
        if ($fontColor !== null) {
            $font['color'] = $fontColor;
        }
        if (count($font) > 0) {
            $body['font'] = $font;
        }

        $background = array();
        if ($backgroundColor !== null) {
            $background['color'] = $backgroundColor;
            $body['background'] = $background;
        }

        $position = array();
        if ($verticalAlignment !== null) {
            $position['verticalAlignment'] = $verticalAlignment;
        }
        if ($horizontalAlignment !== null) {
            $position['horizontalAlignment'] = $horizontalAlignment;
        }
        if ($verticalOffsetInPixel !== null) {
            $position['verticalOffsetInPixel'] = $verticalOffsetInPixel;
        }
        if ($horizontalOffsetInPixel !== null) {
            $position['horizontalOffsetInPixel'] = $horizontalOffsetInPixel;
        }
        if (count($position) > 0) {
            $body['position'] = $position;
        }

        return $this->sendRequest(
            HttpMethod::POST,
            array(
                'config' => $config,
                'body' => json_encode($body, JSON_FORCE_OBJECT),
            ),
            "/watermark/timestamp"
        );
    }