Acquia Auth to Selenium Client for Update (post) then returns status

auth-update.php

    /**
     * Adds auth to update request (post)
     *
     * @param $update
     *
     * @return $update
     */
    function update($update) {
        $request = $this->client->createRequest($update);
        $endpoint = $this->client->getEndpoint();

        // Acquia bit
        $signature = new Signature($endpoint->getKey());
        $acquia_solr_hmac = $signature->generate($request->getRawData());
        $acquia_solr_time = $signature->getRequestTime();
        $acquia_solr_nonce = $signature->getNonce();

        // Add cookies to request through Solarium adapter Zend2Http
        $this->client->setAdapter('Solarium\Core\Client\Adapter\Zend2Http');
        $zendHttp = $this->client->getAdapter()->getZendHttp();
        $zendHttp->addCookie('acquia_solr_time', $acquia_solr_time);
        $zendHttp->addCookie('acquia_solr_nonce', $acquia_solr_nonce);
        $zendHttp->addCookie('acquia_solr_hmac', $acquia_solr_hmac);

        $result = $this->client->update($update);
        return $result->getStatus();
    }