public function deleteMetadata()
    {
        try {
            $params = array('uri' => $this->uri, 'category' => 'metadata');
            $request = new RESTRequest('DELETE', 'documents', $params);
            $this->response = $this->client->send($request);
        } catch(\Exception $e) {
            $this->logger->error( $e->getMessage() . ' in ' . $e->getFile() . ' on line ' . $e->getLine() );
        }
        return $this;
    }