protected function getSuiteRoot(array $suites): \DOMElement
    {
        $testsuites = $this->document->createElement('testsuites');
        $this->document->appendChild($testsuites);
        if (\count($suites) === 1) {
            return $testsuites;
        }
        $rootSuite = $this->document->createElement('testsuite');
        $attrs = $this->getSuiteRootAttributes($suites);
        foreach ($attrs as $attr => $value) {
            $rootSuite->setAttribute($attr, (string) $value);
        }
        $testsuites->appendChild($rootSuite);

        return $rootSuite;
    }