TYPO3 Core

The PseudoSiteFinder aggregates all languages defined in sys_languages and builds from this an array in following form

$languageRecords[$uid] = [
    'languageId' => $uid,
    'title' => $row['title'],
    'iso' => $row['language_isocode'] ?? '',
    'flag' => 'flags-' . $row['flag'],
];

The NullSite class takes this array and creates for every Language an instance of SiteLanguage and gives the per language array as $attributes to the constructor. But SiteLanguage handles following array form

$attributes[
    'title' => ,
    'navigationTitle' => ,
    'flag' => ,
    'typo3Language' => ,
    'iso-639-1' => ,
    'hreflang' => ,
    'direction' => ,
    'fallbackType' => ,
    'fallbacks' => ,
    'enabled' => ,
];

Also hidden sys_languages are inside array, but the enabled field isn't set in the array.