Imbo\Http\Response\Formatter\XML::formatMetadata PHP Method

    private function formatMetadata(array $data)
    {
        $metadata = '';
        foreach ($data as $key => $value) {
            if (is_array($value)) {
                $metadata .= '<tag key="' . $key . '">';
                $metadata .= $this->formatArray($value);
                $metadata .= '</tag>';
                continue;
            }
            $metadata .= '<tag key="' . $key . '">' . $this->formatValue($value) . '</tag>';
        }
        return $metadata;
    }