protected static function checkValidLanguagesIsSet($validLanguages)
{
/** @var LanguageDataProvider $dataProvider */
$dataProvider = StaticContainer::get('Piwik\\Intl\\Data\\Provider\\LanguageDataProvider');
if (empty($validLanguages)) {
$validLanguages = array_keys($dataProvider->getLanguageList());
return $validLanguages;
}
return $validLanguages;
}