protected static function isSerializedResultFromCustomContentElement(array $indexingConfiguration, $solrFieldName): bool
    {
        $isSerialized = false;

        // SOLR_CLASSIFICATION - always returns serialized array
        if ($indexingConfiguration[$solrFieldName] == Classification::CONTENT_OBJECT_NAME) {
            $isSerialized = true;
        }

        // SOLR_MULTIVALUE - always returns serialized array
        if ($indexingConfiguration[$solrFieldName] == Multivalue::CONTENT_OBJECT_NAME) {
            $isSerialized = true;
        }

        // SOLR_RELATION - returns serialized array if multiValue option is set
        if ($indexingConfiguration[$solrFieldName] == Relation::CONTENT_OBJECT_NAME && !empty($indexingConfiguration[$solrFieldName . '.']['multiValue'])) {
            $isSerialized = true;
        }

        return $isSerialized;
    }