EntityImportLoader::getByExternalId

public function getByExternalId($xmlId)
    {
        if($xmlId === "")
        {
            throw new MainArgumentException('Is not defined', 'XML_1C_DOCUMENT_ID');
        }

        $entity = static::getEntityTable();

        if($r = $entity::getList(array(
            'select' => static::getFields(),
            'filter' => array(static::getExternalField() => $xmlId),
            'order' => array('ID' => 'DESC')))->fetch()
        )
        {
            return $r;
        }

        return null;
    }