public function deleteContent($contentId, $versionId = null)
    {
        // 1. Delete the Content
        if ($versionId === null) {
            $this->gateway->deleteByQuery(json_encode(['query' => ['match' => ['_id' => $contentId]]]), $this->contentDocumentTypeIdentifier);
        } else {
            $this->gateway->delete($contentId, $this->contentDocumentTypeIdentifier);
        }

        // 2. Delete all Content's Locations
        $this->gateway->deleteByQuery(json_encode(['query' => ['match' => ['content_id_id' => $contentId]]]), $this->locationDocumentTypeIdentifier);
    }