public function setCellStyle($cellName, array $style)
    {
        //check whether worksheet name is set or not
        if ($this->worksheetName == '')
            throw new Exception('Worksheet name not specified');
        $strURI = Product::$baseProductUri . '/cells/' . $this->getFileName() .
            '/worksheets/' . $this->worksheetName . '/cells/' . $cellName . '/style';
        $jsonArray = json_encode($style);
        $signedURI = Utils::sign($strURI);
        $responseStream = Utils::processCommand($signedURI, 'POST', 'json', $jsonArray);
        $json = json_decode($responseStream);
        if ($json->Code == 200)
            return true;
        else
            return false;

    }