public function getCellsList($offset, $count)
    {
        //check whether workshett name is set or not
        if ($this->worksheetName == '')
            throw new Exception('Worksheet name not specified');
        $strURI = Product::$baseProductUri . '/cells/' . $this->getFileName() .
            '/worksheets/' . $this->worksheetName . '/cells?offset=' .
            $offset . '&count=' . $count;
        $signedURI = Utils::sign($strURI);
        $responseStream = Utils::processCommand($signedURI, 'GET', '', '');
        $json = json_decode($responseStream);
        $listCells = array();
        foreach ($json->Cells->CellList as $cell) {
            $strURI = Product::$baseProductUri . '/cells/' . $this->getFileName() .
                '/worksheets/' . $this->worksheetName . '/cells' . $cell->link->Href;
            $signedURI = Utils::sign($strURI);
            $responseStream = Utils::processCommand($signedURI, 'GET', '', '');
            $json = json_decode($responseStream);
            array_push($listCells, $json->Cell);
        }
        return $listCells;

    }