public function getArtefactsByTypeAndEntityId($type, $entityId)
    {

        // query whether or not, artefacts for the passed params are available
        if (isset($this->artefacs[$type][$entityId])) {
            // load the artefacts
            $artefacts = $this->artefacs[$type][$entityId];

            // unserialize the original data
            array_walk($artefacts, function (&$artefact) {
                if (isset($artefact[ColumnKeys::ORIGINAL_DATA])) {
                    $artefact[ColumnKeys::ORIGINAL_DATA] = unserialize($artefact[ColumnKeys::ORIGINAL_DATA]);
                }
            });

            // return the artefacts
            return $artefacts;
        }

        // throw an exception if not
        throw new \Exception(
            sprintf(
                'Cant\'t load artefacts for type %s and entity ID %d',
                $type,
                $entityId
            )
        );
    }