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

    }