public function getExportFilename()
    {
        $host = php_uname('n');
        $default = $host . '_' . date('Y-m-d_H.i.s', time());
        $filename = array_get(
            $this->manifest,
            'storage.filename',
            array_get($this->manifest, 'storage.file', $default)
        );

        $filename = (empty($filename)) ? $default : $filename;

        if (strpos($filename, static::FILE_EXTENSION) === false) {
            $filename .= '.' . static::FILE_EXTENSION;
        }

        return $filename;
    }