private function addRelations(Repository $repo, MutableBag $relationQueue, Bag $importDatum, MutableBag $relationFields)
    {
        $classMeta = $repo->getClassMetadata();
        foreach ($relationFields as $fieldName) {
            $relationName = $classMeta->getBoltName() . '/' . $importDatum->get('slug');

            $existing = (array) $relationQueue->get($relationName);
            $relatedEntities = $importDatum->get($fieldName);

            if ($relatedEntities) {
                $relationQueue->set($relationName, array_merge($relatedEntities->toArray(), $existing));
            }
        }
    }