private function _openFile($toWrite, $extension, $name)
    {
        $shp_name = $this->_getFilename($extension);
        $result = @fopen($shp_name, ($toWrite ? 'wb+' : 'rb'));
        if (! $result) {
            $this->setError(sprintf('It wasn\'t possible to open the %s file "%s"', $name, $shp_name));

            return false;
        }

        return $result;
    }