Letter::createInstanceById

static function createInstanceById($id = null, array $messageCodes = [])
{
	$code = null;
	if ($id)
	{
		$row = LetterTable::getRow([
			'select' => ['MESSAGE_CODE'],
			'filter' => ['=ID' => $id],
		]);
		if ($row)
		{
			$code = $row['MESSAGE_CODE'];
		}
		else
		{
			$id = null;
		}
	}

	$instance = self::createInstanceByCode($code, $messageCodes);
	if (!$instance)
	{
		return null;
	}

	if ($id)
	{
		$instance->load($id);
	}
	elseif ($instance)
	{
		$instance->set('MESSAGE_CODE', $code);
	}

	return $instance;
}