Service::setLanguage

public function setLanguage($languageId)
{
	$this->languageId = BitrixMainLocalizationLoc::getCurrentLang();
	$dbLanguage = BitrixMainLocalizationLanguageTable::getList([
		'select' => ['LID'],
		'filter' => [
			'=LID' => $languageId,
			'=ACTIVE' => 'Y'
		],
	])->fetch();
	if ($dbLanguage)
	{
		$this->languageId = $dbLanguage['LID'];
	}
}