public function get_file_download_path($download_id)
{
$files = $this->get_downloads();
$file_path = isset($files[$download_id]) ? $files[$download_id]->get_file() : '';
// allow overriding based on the particular file being requested
return apply_filters('woocommerce_product_file_download_path', $file_path, $this, $download_id);
}