CAllIBlockSection::getIblockLanguage

static function getIblockLanguage(int $iblockId): ?string
{
	$result = [];
	$iterator = IblockIblockSiteTable::getList([
		'select' => ['LANGUAGE_ID' => 'SITE.LANGUAGE_ID'],
		'filter' => ['=IBLOCK_ID' => $iblockId]
	]);
	while ($row = $iterator->fetch())
	{
		$result[$row['LANGUAGE_ID']] = true;
	}
	unset($iterator, $row);

	return count($result) === 1 ? key($result) : null;
}