protected function set_path_and_url()
{
$wp_upload_dir = wp_upload_dir(null, false);
$relative_path = sprintf(self::FILE_NAME_PATTERN, self::FILE_BASE_DIR, self::FILE_PREFIX, $this->post_id);
$this->path = $wp_upload_dir['basedir'] . $relative_path;
$this->url = $wp_upload_dir['baseurl'] . $relative_path;
}